Well the good news is, this thread has been very thorough and captured pretty much every complaint I've had, from the information density issue to the performance issues and quality of life issues. The bad news is, the response from the devs has been... Well lets just say I'm not particularly enthused about the "We've decided this is what modern looks like, and if you don't like it, you're the problem" approach to criticism of the changes. Its pretty clear there's strong opinions on the Nexus side as to why a technical modernization in the backend requires throwing out a working design pattern on the front end, even if there's little interest in elaborating on those opinions.
Pretty sure all we can do at this point is vote with our wallets. I've cancelled my auto renewal. NexusMods can, and will, do whatever they like with the site, that's fine. But we don't gotta pay for it.