For people I don't know or just started talking, I give them my telegram username that's not linked to my personal phone number. For friends and family, I use signal.

Lots of opensource projects have telegram channels for updates. Not to mention news and local updates as well.

People need to incorporate a social aspect of the real world. Everyone isn't as privacy conscious as you are and you can have multiple apps for different scenarios.

If you don't ever want to meet anyone new, signal is perfect.