Signal is great and I believe it does have better crypto. But the UI is severely lacking along with feature set.

Telegram feels like it's adding something new every few months, though the documentation over the features is poor since it's mostly through announcements. It's also a lot more customizable. I ultimately settled on Telegram because it was a good balance of feature-rich and crypto (when you use it)

That being said, it was hard enough to get a small group of friends to transition to Telegram. Signal would be much harder due to not having so many niceties.

I wish both to continue competing against each other, though. It's great to have choices that aren't owned by the big corporations.