• persistent IRC style chat rooms
• virtual “servers” to organize said chat rooms, manage privileges, control visibility
• integration with bots for all sorts of things (moderation, user welcome, dice rollers, etc.)
• integration with games/music players/etc (I don’t use it but it’s very popular)
• privacy and moderation controls
• client allows fine grained notification controls
• voice, video, and screen casting simultaneously
• “server” templates: use an existing server config (roles, permissions, rooms, etc.) when creating a new server.

That’s just off the top of my head.

It’s enshittifying, but the value proposition is still hard to beat. I’m really hoping Matrix catches up with the feature set soon.