I made a clean break (never installed WhatsApp in the first place, in fact). I got many friends to install Signal and use it to contact me, but only since other people have started using it as their preferred messaging app as well is it reaching critical mass - friends who are not on Signal are now starting to use it due to FOMO.

So what I'm trying to say is: I've seen your strategy working, so it's a good one that doesn't require you to make too many personal sacrifices.