Thats true, Telegram has very good UX. But bullshit crypto with a closed server etc. :-(
Telegram proves that to have even better UX, you need to sacrifice security (and privacy).
I can understand that they have limited funding and want to focus on the security features first and foremost, but that makes it really hard for me to get some of my friends to use it.
Having said that, I agree that Signal's UX is not bad, just that it could be better.
Telegram went UX first and turned down the crypto so that I can install Telegram on a fresh laptop and I've instantly got the same chats, with history, as I do on my phone.