Discord is very popular with the gaming community.
When Schools shut down for Covid in 2020, my daughter the teacher started doing classes over Discord, which makes it pretty neat. (The kids were like "Whoa Ms Westfield!! You're a GAMER?!") (the schools later settled on Zoom, once they had a chance to think and standardize, but ... high points for applications that are quickly repurposable like that.)
I find it's time-oriented many-in-one-place conversations much inferior to the Discourse Forums topic-oriented conversations, but some people (especially young people) seem to prefer it.