I disagree that existing NNTP clients are clunky. If anything, I find existing web forum software clunky. SSC is my go-to example because it's where I ended up in the diaspora fallout. It gets on the order of seventy comments a day and is incredibly unwieldly to navigate. And it's a single site. In Usenet days, with native clients, I routinely perused groups with an order of magnitude more discussion and had zero trouble navigating -- and the same interface worked for all groups. It is this form of convenience I would like to revive. It cannot be done in a browser -- but it doesn't need to be. The end goal is for the browser to be the non-trivial-inconvenience-provoking default, but for native clients to be an option for people who want or need the kind of power they provide.

It's relevant to the GG and ephemerality objections that while I'm suggesting NNTP, I'm not going to suggest Usenet itself; but rather, a private network, containing only LW-related groups, with infinite retention and programmably dumpable content. i.e. there is no risk of losing anything. Sequences may be an issue, but because of curation limitations, not retention. (also, yes, GG is a godawful sack of shit and Google has atrociously mismanaged their possession of a cultural treasure trove)

I actually think the existing LW/reddit-style interface has the least-horrible UX of web-based discussion software out there. I wouldn't object to keeping it looking more-or-less the way it does; my problem is with mechanism more than policy.