DeletedUser227 Those who did care about staying in touch with me did get yet another messenger. Works well for me. As for the rest, they can use postal services or see me in person.
DeletedUser218 In regards to quitting WhatsApp, I can't. All my "friends" are on there and important contacts who won't definitely switch.
brandy078 If you are important for those contacts too, they maybe will switch.
Yes, if you are important to someone, they will install another messenger like Signal too. When I did this years ago, Signal was not even that widespread. But now, some of those people who installed Signal mostly to stay in contact with me, are getting more and more contacts and even whole groups on Signal, which is great.
I do recommend to keep the entry "fee" low though, meaning choose an app which is very similar to what they already use. Signal is a good candidate for that. Threema is as well, but unfortunately lots of people are not willing to pay coffee money for a messenger app...