Telegram doesn’t enable encryption by default, and it might be tricky for new non-tech savvy to understand how to enable and use it (because most of the time they will just send it to the non-encrypted chat).

Signal is open source, not like Telegram that is closed source AND proprietary.

Telegram for public group chat, Signal for the friends & family. You can just register it on a number that is not linked to your ID, but friends won’t be able to discover you directly, and you will need to message them and that will give them your number that is supposed to be « anonymous », and I don’t really trust non savvy tech with keeping my number safe.