I mean, there's matrix. Just because you can federate, doesn't mean you have to. You can run it in isolation (in fact, it's even easier). Additionally, you don't have to care about or enable encryption either.
Matrix also has nothing to do with UI or UX. The clients do. Write a new client if all you care about is UI/UX. You have a much higher chance of success.
Matrix also has nothing to do with UI or UX. The clients do. Write a new client if all you care about is UI/UX. You have a much higher chance of success.