TLDR: The r/selfhosted subreddit has a Discord server. The owner’s account got hacked leaving the server in a precarious state. They submitted a support ticket, but Discord has not taken action in weeks and probably won’t at all, so they are considering starting a new Discord server.
XMPP is all the goodies of IRC but modernized for the current age, and it’s not a nu-protocol like Matrix so it’s quite lightweight to host or service.