Small list I have put together for alternatives to #discord
I am looking at this from a non-technical perspective...

Willing to hear about other platforms though/

#Matrix = YES = BUT Onboarding is difficult.
#Root = MAYBE = US-Based... Has funding from Crunchyroll founder

#Stoat / #Revolt = YES = Has potential, needs time to develop.
#Spacebar = NO = Not actively developed. (Last commit 10 months ago)
#TeamSpeak 3/6 = NO = Requires joining voice channel in order to text chat.

I updated #Stoat to YES from NO as it seems to be better than what it was previously, but there are some features missing from Discord that some people would be losing out on.

@pandooroo informed me of #Fluxer, and it is a near 1:1 clone. It reminds me of early Discord (circa 2016/17) - Better Linux support and a proper mobile app would go a long way.

@padraig Another alternative is actually Steam Groups.

They support text/voice chats, pretty much everyone already has Steam installed and joining groups is a complete non-issue.

For people who use Discord as a way to stay in touch with friend groups, i don't see any easier path.

https://steamcommunity.com/updates/chatupdate

@padraig Stoat is not "UK based", it is an open source community driven project. User data is stored in EU servers and the vast majority of its contributors aren't even from UK.

Still has round egdes, but the only thing really missing is video sharing. For now, it's the best alternative we have. Especially in terms of future developments.

@SgtRenny I will need to revisit this as it has been a couple of years since I used Revolt/Stout. I wonder how easy it is to get their self hosted stuff up and running.
@padraig Spacebar is consistently developed! You might've been looking at the last landing page update?
Though it's worth noting it's a Discord reverse-engineering project, rather than aiming for being the new alternative chat platform
™️. That said, federation is planned, but is not priority.
@emergencygg There was no commit since April, until the 11th (the day after I posted this) to say "Bump commit date so we don't seem dead". I did check the other repos and other than 'chore' updates, I didn't see anything else being committed. Happy to be proven wrong.
@padraig Yeah, the one with the bump is the landing page! The development is in the server repo (screenshot attached). We might have different ideas of what count as chores, but I can say voice chat, which is currently disabled on the official instance while being debugged, has only even worked since November last year, which is a pretty big addition.