What alternative is there that has: screen sharing, voice calls, all your friends across every community in one DM list, meaning that you can make group chats across communities?
But once the company locks me out, I would neither have screen sharing nor video calls nor the DM list. Isn't it better to just use Matrix which may have less features but those features I can rely on for a long time without the risk of being locked out?
Some people refuse to get in the ocean for fear of being killed by a shark. Most people swim, boat, surf, parasail, etc and enjoy that aspect of their life without more than the most casual thought of sharks. Neither group is right but one group has a much more enriched life…assuming they don’t get eaten by a shark of course.
Maybe (like most people), you never get locked out.
You can be stubborn and rely on a platform your audience/community probably doesn’t want to use and have a very steep uphill battle to success. Or you can take a risk and rely on a platform you don’t own and have a (somewhat) less steep uphill battle to success.
If the platform is good enough and the benefits of using it are significant enough, people are going to take the risk. See: App Store development, selling on Amazon instead of your own e-commerce store, etc.