As you say, Element is superior technically and in my experience has a better UX/UI (simple sign up, no need for phone numbers, and straightforward chat app).

I don't recommend Signal due to the, as you say, inferior technical aspects, the phone number dependency security issues, and the centralized single point of failure (recall the huge, day long outage they had a few weeks ago)

I use Element as my primary chat application, across platforms like iOS, web and android, and I've never seen it load. I use it with friends, colleagues and with my 73 year old mum.

Bonus points because it's in F-Droid, too!

Basically, it's just great, in my opinion!