You can install Telegram with f-droid, and it works well on a degoogled phone. Signal forbids alternate clients and is not on f-droid. It's thus just not an option.
It was mainly moxie who was hell-bent against that though. I'm hoping they'll reverse their stance since he left. And on federation as well.
Moxie was against all these things because it would make new features more difficult to implement. But personally I care much more for an open infrastructure. Most of their new features weren't even useful.
I'm currently using a matrix bridge and I didn't get banned (officially that's a third party client too) so that's a good sign.
