here you have chart comparison
https://www.messenger-matrix.de/messenger-matrix-en.html
and alternative
https://www.securemessagingapps.com
personally I like Element (Matrix) and Threema
edit: btw. signal best UX? do they finally show users how to force send unencrypted SMS or you still have figure it out with google? I remember their great UX when they were forcing PIN verification with nag screens taking half or whole screen, which was the last drop I moved with whole family away from that PoS, let alone how unreliable it was, whole network down because admin in US sleeping waiting hours until he fix it, their approach (aka hatred) to users reminds me Firefox devs, left Signal even before it became popular
That's a nice comparison table.
You can run your own matrix server but tbh it’s easier for someone else to do it.
Not to mention the obvious advantages of their bridges into the closed networks of WhatsApp/fb/x/instagram etc
the best on ux is probably telegram, but i'm trying to move a few people off it anyway