What are the critical features of Discord?
- group chat with history and some degree of searchability
- forums (but with more realtime features so it works a bit closer to a chat)
- voice calling, including groups
- video calling
- screen sharing
- mobile app with much the same features as desktop
- web app, ditto.
- “ownership” of specific spaces (“servers” in discord context)
- solid permission setup for visibility (like “roles” in discord)
- trivial startup effort
Other less-critical but still potentially important features:
- markdown-like formatting in posts/messages
- grouping of channels
- intermix of “forum” spaces with “groupchat” and “voice/video” spaces
I don’t know of any that cover all of those, and ymmv on how critical some of these are.