Discord is a serious thing now, I've seen enterprise products add support for Discord before Slack.
Discord is a serious thing now, I've seen enterprise products add support for Discord before Slack.
Discord is actively hostile to users by randomly banning and/or phone-walling users, especially any browser or connection that cannot be fingerprinted well enough, and giving them no recourse at all, just saying "yep our automated system is working, bye". There's so many more awful things they do, just search this site to find lots more.
Anyone who figures out how to have pseudoanonymous identities that can't be endlessly minted to evade bans that doesn't involve aggressive fingerprinting will be the internet's favorite child overnight.
OSS communities, yes. More and more FOSS communities are on Matrix, either using matrix.org or connecting their own instance to the network. FOSS projects using FOSS tools, and decentralized for that matter too.