A little more thinking re: platforms and people.
I tend to think people stay on platforms, even platforms they don't like, because they have developed relationships with exclusive resources on that platform, like products, art, or people. In the case of people, leaving the platform can meaning leaving friends that are not reachable in other ways.
Now, though, it occurs to me that if those friends will not communicate with someone outside of a particular platform (assuming a non-onerous alternative is available), are they really friends?
I think they are like the kind of friends you might have at a club sport. You are friends when you are doing that activity, but if you leave the club, you won't hear from them again. The club and sport is the thing for them; and you are nice company.
I think this is fine, as long as you understand what it is. There's a lot of Twitter and Facebook that don't, and as a result, overvalue the criticality of those platforms.