For most people it's hard to trade comfort against freedom. They feel safe in their known environment, even if it's a cage.
One can only escape from prison when he realizes he's in one.
You could tell them from your adventures behind the walls, so they become curious to see it by themselves. If they aren't interested at all then it might be the best to leave them there. You will find new friends with similar interests as yours.
I never try to push anybody to switch to what I use. I even turned off the invitation messages.
As I never used FB, WA or anything from that corner, text messages were one common channel with some of my contacts.
Funny enough, over time Signal occasionally reports that yet another person from my address book is using Signal now.
The same is true with Threema, although there is no free version of that app available.
Smart people find the right path sooner or later.
@fredl99 I completely agree with your thoughts. As you've said before, people are not really aware about what tech companies are doing with the internet, or if they are, they do not see palpable consequences in order to worry; they only think of privacy violations as a conspiracy theory. All I can do is make available to my close friends other options.
Fosstodon is an English speaking Mastodon instance that is open to anyone who is interested in technology; particularly free & open source software.