I think what it boils down to is hackability. The friction comes from people being unable to modify their experience, or the experience of their users, without going through this crazy process that involves it going all the way up to two Lemmy devs for the entire universe of users, and then something getting changed, and then it going all the way back down to the moderator or whoever, after the site admin upgrades the entire site. Or, going rogue and starting to change the code for their instance, which of course only the admin can do and voids the warranty.
I wasn’t trying to become a Lemmy dev. I just wanted to make my instance neat, and I like to tinker. But I’m glad that people took the question seriously enough to give real, detailed answers about what would make things better. Lemmy is already designed to separate the backend and frontend very cleanly. I think it wouldn’t be too hard (famous last words…) to make the frontend more hackable to make at least some of these into easier things to do at an end-user or end-administrator level.
It might be good to look at other software, too. I was thinking Lemmy, but the goal is the neat stuff, not the Lemmy part of it.