I saw an interesting comparison the other day. If this was a message board from the early 2000s, and the moderator was deleting posts, you move on, not throw a giant fit about free speech using some one else server.
Insofar as they're monopolies, they should be managed by the people as if they were a public space.
This would be similar to the central area of a mall or when companies provided housing to workers to prevent unionization efforts. Both places were upheld as places where the First Amendment must be upheld, despite private ownership.
A lot of people look at this issue and see two groups fighting over it. There are (at least) three groups though: for, against, and undecided. This is really a fight about how to convince the undecided, so solutions like "go make your own platform" aren't desirable; undecideds aren't going to know about the new platform, and won't automatically appear en masse on it, so it actually makes reaching them more difficult.
> You're still free to send a text, write a letter, call
Exactly. This is why free college and free medical care are not necessary.
You can learn from public libraries and go to the forest and apply herbs when you are sick.
Though tbh I'm not totally sure what point you're trying to make.