@Zeno from my experience it is necessary to first leave the platform, before people follow you to another one. Also not everyone can be convinced to do that, but in my case most of the people, who are important for me are on Signal or XMPP now. :) But it took a quite long time.
I'll at least try to get them to switch at the same time. Yeah, I get that, but I still have hope^^
@Zeno For the network effect? Thats a smart consideration, but it's only works if you can convince them that it's really a better solution to use. I noticed that some people I convinced to install Signal / Conversations to communicate with me, are still chatting over WhatsApp with each other... That was a little fist in my face, calling me the reality that many people don't care about privacy. On the other hand it was a compliment, that they installed it just for me. But still...
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.