Here in the NL it's almost like some kind of privatized utility. It's used for sensitive things too.
A while ago there was an audit: Lo and behold the backups weren't e2ee. What ever happened to warrants?
Well I just told everyone I'm switching a few years back and that's that. And actually a lot of people switched because they preferred it over email and SMS.
It's best to avoid trying to persuade others. Just say how they can contact you and leave it at that.