Don't use messengers that ask for your phone number and aren't end-to-end encrypted. Use services that store as little data as possible. If data is stored, it can be given away and I would assume that it will be given away. Telegram disguises itself as encrypted chat app, when it is actually just a regular centralized plaintext messenger that has an encryption feature that nobody uses.
TLDR don't use Telegram and Signal as some "alternatives" Use Matrix clients (Element, Fluffy chat) or Session, Briar (no (video)calls), Delta (no (video)calls), Jami, not recommending Threema because they can tie you through payment and it's centralized Here simple chart to see what to use and not use (use translate feature): https://www.messenger-matrix.de/messenger-matrix.html
>Use Matrix clients (Element, Fluffy chat) or Session, Briar...
With those other clients you mention, one of the reasons your communications will remain secure is that --because so few people use them-- you'll struggle to find anyone to message, in the first place.