My social group are moving to a private IRC server already. This is probably the best outcome really. I don't think any of us are under 50. But we have relatives who remember when this would have resulted in some of us being killed. I wish I was sensationalising but I'm not.
For the happy-clicky-emoji types one can put TheLounge [1] or Convos [2] or other web front-ends [3] in front of IRC. They don't scale as well but it would allow for those that don't care for the underlying IRC network. If it does not exist yet there is probably a way to write in a voice chat link handler for Mumble. It's a separate app but very low CPU/memory footprint and maybe that could weed out some low quality members.
I set up this exact combo (thelounge + mumble) for my friends last night after this news. It's not a complete 1:1, but I think it'll meet our needs. I'm going on a road trip and as a fun experiment I'm going to try to get Claude to churn on integrating Mumble into thelounge, somehow, to mimic the Discord client. I'd really prefer something other than Jitsi for screen sharing, since I'm a weirdo and don't like the UX of making a 'call' and much rather prefer the 'hop in' style VC like Discord or Mumble.
Nice. If you do happen to integrate Mumble into one of the web front-ends please consider sharing it with them upstream so others may benefit from your work or perhaps just share a git repo with your patches. I am certain others would appreciate that.
Indeed it is not as polished and refined as the commercially supported service. Even if the self hosted services people stand up do not gain the same popularity as Discord they are nice to have when Discord is down or if people want to share something too sensitive for a corporation and their third parties to be trusted with.
On the plus side assorted IRC daemons have been around long enough that one can find Docker or Ansible examples to get started. More complex but popular IRC daemons such as UnrealIRCD [1] can be a little daunting at first yet have all the configuration directives and modules one could likely ever need. Many capabilities can also be disabled for simple setups. One of the simplest IRCD's to set up is ngIRCd [2]. I think the fastest I have set up ngIRCd including LetsEncrypt certs was around 5 minutes but that is because I get wildcard certs.