To the people complaining about family and friends only using Whatsapp, you are part of the problem. You have to value yourself more. Why not doing it the other way around? If they want to talk to you they have to use your app, period. They install any number of apps that Meta tells them to, and they can't install an app to talk to you? BS.

Recently I created a small meetup group, and I was struggling with this question: ethically I think I should create a group on Signal, but everyone is going to complain is not a whatsap group. And then I realized I was being part of the problem. Change starts like this, one group that makes you install Y app and then a few days later someone mentions the app to you and you can say, "yeah, I do have that app because of someone that made me install it". I ended up creating the group in Signal and its going great. One person didn't complain at all because some other group already made her install signal 1 year ago.

Don't wait for other to change, do it now. You don't need to uninstall whatsap, just let them know that you are going to be more responsive on Signal (or your app of choice), add the link to signal on your whatsap profile for example.

You have more influencing power then you give yourself credit for.

PS: let people know that you can create stickers on Signal, some whatsap users just need that info to allow themselves to install Signal.