Transitioning ones social network from one system to another can be a heavy lift. It is not the act of a single person, it is the act of a community. If you want it to happen, you can be a leader in your community. You can make it be:
A game: let's try something new, something safer, something cool!
An invitation: I'm going to try moving over here for a while, I'd like you to join me.
A protest: We should stop supporting the platform that treats us like that, and start supporting the one that treats us like this.
Baby steps: I'll meet you where you are for now, we're not abandoning you. Come over here when you're ready.
https://www.wired.com/story/a-simple-whatsapp-security-flaw-exposed-billions-phone-numbers/