I'd like to start giving people the option of commenting on shorter Cold Takes pieces (which I don't cross-post here or provide audio for). I'm going to use this post for that: I will generally leave a comment for each piece, and people can leave their comments as replies to that.
Holden, have you had a look at the Terra Ignota series by Ada Palmer? It's one of the better explorations of a not-quite-Utopia-but-much-better-than-our-world that I've come across, and it certainly contains a large degree of diversity. It also doesn't escape being alien, but perhaps it's not so alien as to lose people completely. My one caveat is that it is comprised of four substantial books, so it's quite the commitment to get through if you're not doing it for your own leisure.