I noticed one substantial change to my workflow when I got a new laptop with a wider screen than my old laptop. The new screen is wide enough that I can now easily look at two windows at the same time, one on the left and one on the right (and I could also drag windows to the side and they would resize appropriately). This ended up being more useful than I had anticipated; for example, I can now read a .pdf and edit a .tex file at the same time, or open up Workflowy twice and look at one part of my Workflowy while editing another. Programmers value having multiple monitors for similar reasons (see e.g. here). In some sense it increases your external working memory.

Edit: Something I was trying to say implicitly that I might as well say explicitly: consider your computer desktop part of your space too. If you're anything like me, you pay much more attention to it than to your actual desktop.