juanbur one more thing: My best friends don't give a damn about privacy or are very selective/ambivalent when choosing what tech to trust. E.g. one of them is super careful not using Facebook, but then turns around comfortably using WhatsApp, Discord, Opera browser all running in the background. It's fun sometimes to look at from the outside, but all you can do is giving hints here and there and not be annoying about it.
A good friend will respect your threat model and you should respect theirs. My friends installed Signal to stay in contact with me, and I'm okay that they give my number away to WhatsApp etc.
Don't try to change people. The most important thing is to have common values and interests to build on, and it won't always be privacy or cyber security.