if people value it, they would move to a site that cares about it. But it seems people value community the most, and the only options with large community is Discord, Twitter, Facebook, Instagram, or Tiktok (maybe a half dozen others, but not many more than what I listed).
You pick your poison. Discord is definitely the best of those alternatives in my eyes. FB/Instagram/Tiktok aren't meant at all for text, and Twitter has never been for long form discussion.
Admins value single login and anti-spam. Plain and simple.
I am perfectly capable of running a foum, bulletin board, Discourse, whatever.
What I am NOT capable of handling are secure logins and anti-spam. Everybody is heading to Discord simply because Discord handles those two problems for you.
The problem is that centralization allows you amortize the cost of handling those two issues. Decentralized systems that don't handle those two things will never catch on.
It would be a pity to lose Reddit. I don't know if that's what must happen: it's not up to me.