Give other matrix clients a try: FluffyChat has separators for DMs, Groups, and Spaces.

Cinny has a Discord look. Mainly a desktop application so it doesn’t have an app, but works fairly well as a PWA.

If you’re on Android, Schildi Chat Next also has a lot of UI/UX tweaks that people enjoy.

Usability is good in my opinion. They’ve spent a lot of time on the UI over the past couple years. The mobile Element X apps are excellent now IMO. But the two things that prevent matrix/Element from being a good discord replacement are:

1. No Mumble-like voice chat. They have Zoom-like conference calling now, but no voice channels.
2. Search is either non-existent (mobile clients) or is awful. It’s somehow worse than Discord’s search! I know it’s because the search needs to work on-device because of E2EE, but unfortunately it’s still a minus point vs Discord.