Communities need associative hosting. Following Freenode's well documented collapse, we were motivated to set up haskell.social, an experimental web, matrix, and pleroma set of services to give the haskell-adjacent community an alternative to centralized services like Meetup, Slack/IRC/Discord, and Twitter, etc.
Federation enables people to bring their own identities and connect with other communities online. A recent blog post highlights the importance of self and associative hosting.
Matrix and pleroma certainly have their downsides and IRC and Twitter are pretty hard to beat, but they have their upsides as well. Indeed, much of the haskell community is already supported by the new Libera Chat IRC. haskell.social is an alternative, enabling experimentation with newer federated approaches to online communities.