You only need two friends and a chat server to have a community. I've been running one for my friends, like a self hosted discord, for almost ten years. It is by far my most valuable online space. There's maybe a dozen users. Whatever. It's great.
For a wider net, I have a self-curated feed on Lemmy and Mastodon. It's super clean and positive compared to suggestive social media.
The old Internet will never be back, but The Good Parts still exist and can be remade. I don't have to visit the shitty parts.
What I don't like is when people wants to use a chat group where a forum would have been more useful.
How does one achieve this?
There are also some FOSS Discord clones in various states of maturity
I'm administering both Matrix/synapse and XMPP/prosody servers and I wouldn't do the former if it wasn't my job.
This doesn't solve any of the other problems (what happens when Discord enshittifies? Is it acceptable that Discord updates basically every single day? Is it OK that they constantly advertise video games in the form of little notifications saying "stream 30 minutes of _____ to a friend and unlock an avatar for your profile!"?) but it does seem to solve the 'how do I have a platform for my friends and I to talk" one.
Sounds like enshitifications has begun already