A great example of a product actually changing for the worse is Microsoft Office. Up until 2003, Microsoft Office had the standard "File, Edit, ..." menu system that was characteristic of desktop applications in the '90s and early 2000s. For 2007, though, Microsoft radically changed the menu system. They introduced the ribbon. I was in school at the time, and there was a representative from Microsoft who came and gave a presentation on this bold, new UI. He pointed out how, in focus group studies, new users found it easier to discover functionality with the Ribbon than they did with the old menu system. He pointed out how the Ribbon made commonly used functions more visible, and how, over time, it would adapt to the user's preferences, hiding functionality that was little used and surfacing functionality that the user had interacted with more often.

Thus, when Microsoft shipped Office 2007 with the Ribbon, it was a great success, and Office gained a reputation for having the gold standard in intuitive UI, right?

Wrong. What Microsoft forgot is that the average user of Office wasn't some neophyte sitting in a carefully controlled room with a one-way mirror. The average user of Office was upgrading from Office 2003. The average user of Office had web links, books, and hand-written notes detailing how to accomplish the tasks they needed to do. By radically changing the UI like that, Microsoft made all of that tacit knowledge obsolete. Furthermore, by making the Ribbon "adaptive", they actively prevented new tacit knowledge from being formed.

I was working helpdesk for my university around that time, and I remember just how difficult it was to instruct people with how to do tasks in Office 2007. Instead of writing down (or showing with screenshots) the specific menus they had to click through to access functionality like line or paragraph spacing, and disseminating that, I had to sit with each user, ascertain the current state of their unique special snowflake Ribbon, and then show them how to find the tools to allow them to do whatever it is they wanted to do. And then I had to do it all over again a few weeks later, when the Ribbon adapted to their new behavior and changed again.

This task was further complicated by the fact that Microsoft moved away from having standardized UI controls to making custom UI controls for each separate task.

For example, here is the Office 2003 menu bar:

(Source: https://upload.wikimedia.org/wikipedia/en/5/54/Office2003_screenshot.PNG)

Note how it's two rows. The top row is text menus. The bottom row is a set of legible buttons and drop-downs which allow the user to access commonly used tasks. The important thing to note is that everything in the bottom row of buttons also exists as menu entries in the top row. If the user is ever unsure of which button to press, they can always fall back to the menus. Furthermore, documents can refer to the fixed menu structure allowing for simple text instructions telling the user how to access obscure controls.

By comparison, this is the Ribbon:

(Source: https://kb.iu.edu/d/auqi)

Note how the Ribbon is multiple rows of differently shaped buttons and dropdowns, without clear labels. The top row is now a set of tabs, and switching tabs now just brings up different panels of equally arcane buttons. Microsoft replaced text with hieroglyphs. Hieroglyphs that don't even have the decency to stand still over time so you can learn their meaning. It's impossible to create text instructions to show users how to use this UI; instructions have to include screenshots. Worse, the screenshots may not match what the user sees, because of how items may move around or be hidden.

I suspect that many instances of UIs getting worse are due to the same sort of focus-group induced blindness that caused Microsoft to ship the ribbon. Companies get hung up on how new inexperienced users interact with their software in a tightly controlled lab setting, completely isolated from outside resources, and blind themselves to the vast amount of tacit knowledge they are destroying by revamping their UI to make it more "intuitive". I think the Ribbon is an especially good example of this, because it avoids the confounding effect of mobile devices. Both Office 2003 and 2007 were strictly desktop products, so one can ignore the further corrosive effect of having to revamp the UI to be legible on a smartphone or tablet.

Websites and applications can definitely become worse after updates, but the company shipping the update will think that things are getting better, because the cost of rebuilding tacit knowledge is borne by the user, not the corporation.

I think the most basic and true explanation is that the companies we are thinking about started out with unusually high-quality products, which is why they came to our notice. Over time, the conditions that enabled them to do especially good work change and their ability tends to regress to the mean. So then the product gets worse.

Related ideas:

• High-quality product design is not very legible to companies and it's hard for them to select for it in their hiring or incentive structure.

• Companies want to grow for economy-of-scale reasons, but the larger a company is the more challenging it is to organize it to do good work.

• Of course, doing nothing at all seems ridiculous, particularly so for companies whose investors all invested on the premise of dramatic growth.

• In many cases, a company probably originally designed a product that they themselves liked, and they happened to be representative enough of a potential market that they became successful and their product was well-liked. Then the next step is to try to design for a mass market that is typically unlike themselves (since companies are usually made up of a kind of specific homogeneous employee base.) That's much harder and they may guess wrong about what that mass market will like.

As a control, you could look at Craigslist, which hasn't changed its appearance for about 25 years, but is still the most popular website in its category according to SimilarWeb.

And if the changes are actually just bad by and large (I'm inclined to agree with the above infographic about Reddit) then why do websites get worse, rather than better, over time?

I think the reason it seems bad is because old users like you are not who the company is trying to attract. They’re trying to attract new users. Or the marginal user. So they make their website, logo, and interfaces more to that marginal user’s pleasure. I’d claim that according to that metric, which is of course a very different metric than the pleasure of the people presently on the platform, the websites you list all did very well.

See also: The tyranny of the marginal user

Maybe the average design is bad, so good designs becoming worse after redesigns is just regression to the mean.  Bad design is not the exception - bad design is the norm, and good design is the exception.

I have had the chance to watch software get made up close at several jobs, and this seems to track.  Even designs that seem to be good normally aren't, and the having to add features normally makes the design worse (less usable, less clear) without a herculean effort against that tendency.

I'm about 40 pages in to Don Norman's The Design of Everyday Things, which seems to be the seminal text on this sort of thing, and even this early in the book it's clear that there's far more ways that a design can go wrong than ways than it can go right.  Design is hard.

One counter-example I experienced this year: From what I can tell, Steam's client re-design (from 2023~05) was uncommonly well-received, or at least that's the impression I got from the discussion on reddit.

I think it's mostly that people complain when something gets worse but don't praise an update that improves the UX.

If a website or app gets made worse people get upset und complain, but if the UI gets improved people generally don't constantly praise the designers. A couple of people will probably comment on an improved design but not nearly as many as when the UI gets worse.
So whenever someone mentions a change it is almost always to complain.

If I just look at the Software I am using right now:

• Windows 11 (seems better than e.g. Windows Vista)
• Spotify (Don't remember updates so probably slight improvements)
• Discord (Don't remember updates so probably sight improvements)
• Same goes for Anki, Gmail, my notes app, my bank app etc.

All of those apps have probably had UI updates, but I don't remember ever seeing people complain about any of those updates. I use most of those apps every day and I hear less about their UI changes than about reddit's, a website I almost never use, people just like to complain.

How good was the Spotify UI 10 years ago?  I have no Idea but I suspect it was worse than it is now and has slowly been getting better over the years. 

I also looked up the old logo and it's clearly much worse but people just don't celebrate logos improving the way people make fun of terrible new logos.

All companies and products get changed over time.  And they're optimizing on multiple dimensions, some of which are cost and complexity of delivery, attractiveness to new users, usability by existing users, and different segments of paying customers (including, usually, advertisers and financiers).  

In MOST cases, there's a selection effect of early (or current) users liking things well enough to overcome the hurdles of use, so many changes that are to optimize for other stakeholders (especially the very important potential users who haven't yet started using the product) are likely to seem counterproductive to those who find it good as-is.

Add to this the uncertainty of WHAT precisely makes it good, and what will make it better for the target subsets, and a lot of changes are just bad, but there's no way to know that without trying it.   And it's known that many changes are path-dependent and change itself bothers many, so undoing a neutral or somewhat negative change (even when very negative to some users) is often seen as more costly than leaving it, and making other changes later.

One possible factor I don't see mentioned so far: A structural bias for action over inaction. If the current design happened to be perfect, the chance of making it worse soon would be nearly 100%, because they will inevitably change something.

This is complementary to "mean reversion" as an explanation -- that explains why changes make things worse, whereas bias-towards-action explains why they can't resist making changes despite this. This may be due to the drive for promotions and good performance reviews; it's hard to reward employees correctly for their actions, but it's damn near impossible to reward them correctly for inaction. To explain why Google keeps launching products and then abandoning them, many cynical Internet commentators point to the need for employees to launch things to get promoted. Other people dispute this, but frankly it matches my impressions from when I worked there 15 years ago. It seems to me that the cycle of pointless and damaging redesigns has the same driving force.

I’m not convinced that the new reddit example is worse than the old one. They serve different purposes, the new one lets you actually read the posts without having to click in. It’s also more pretty and clean - I expect the median and modal user to like the new UI better even if it less useful to reddit powerusers.

Capitalistic forces causes companies to converge on design that most people find intuitive, and this is good

Everything gets worse with size more than time (not strictly time, but activity, updates, manhours, whatever you'd call it).

Steam has a small team, so the degeneration of Steam has been slow, and it's still mostly a good company. But I'm starting to see some appeal which is not geared towards users (Wokeness¹), and some bloat (my Steam client is constantly using like 1GB of memory).

I think that if you have something good, and you change it, then you tend towards something different which is not necessarily good. There also tends to be various "creeps", like power-creep, feature-creep, software/code bloat.

I suppose that you can tell enshittification by who benefits from the updates. But even wanted updates can ruin a product, which is a different mechanic. Let me expand on this before I get more downvotes. There's a cool post online called "Warrens, Plazas and the Edge of Legibility" which compares "Warrens" and "Plazas". The following is my own, I'm mainly just borrowing their terms: Things currently tend towards Plazas, resulting in more openness of information, this makes things like moderation easier, but it also makes it easier to game the platform and to "expose" things that only a minority of people will like, which leads these things getting negative pressure from the outside. Two additional results of this is that platforms become more artificial, and that they lose the appeal of hidden value usually given by the "fog of war" so to speak. Video games lost part of their soul with the appearence of online guides and meta-strategies. Dating apps suffer from bots and meta-gaming as well. My answer covers all these examples, I'm speaking extremely generally and listing the abstract patterns.

A final way I've seen things degenerate is with regulation. Bad actors abuse the product, changes are made to stop the abuse, but at the cost of making the product a little worse. The bad actors find a new thing to exploit, and this repeats until the process generally sucks for everyone (Compare airports now to 25 years ago. Also the internet).
This last issue can't be helped for anything big. Once you have the size of say, Twitter, you're forced to ruin your product in order to keep the government, public opinion or the media from ruining your image. There's no real way to fight against this, search engines (and cloudflare, etc.) will blacklist you. The reason this will happen is that a small portion of any big group is extreme in some sense, say mentally ill or aggressive. This minority will sooner or later cause some event which gets a lot of public attention. Smaller companies/websites/communities/services do not run this risk.

Everything grows and dies, be it software, people, trees or nations. The only difference is how many years each generation lasts (and this is more or less proportional to size, perhaps following a powerlaw or something).

Edit: Accidentally double-posted as the servers had a hiccup, my bad. And let me see if I can add links.

1: https://store.steampowered.com/sale/lgbtq-sale (Admittedly I can't seem to find more examples now. I might have confused Steams official position and the poor moderation of the Steam forums)