But the thing is, ultimately, that your speech does not need a platform, let alone a specific platform, to be speech. "I can't speak freely because Platform A

But the thing is, ultimately, that your speech does not need a platform, let alone a specific platform, to be speech. "I can't speak freely because Platform A won't carry it" isn't a thing when Platforms B through ZZZ exist. And if B through ZZZ have less reach, well, so be it.