"Freedom of speech" is a philosophical concept, not a legal principle. You seem to have it confused with the US-specific "First Amendment", which is the one that only applies to the government.
I personally see a big problem with social media banning trans-people (Facebook), or declaring that the whole LGBT crowd is inappropriate (Livejournal, Tumblr). I think it's a problem when scientists sharing Covid-19 information get banned for being ahead of the official CDC/FDA guidance (Twitter)
Maybe the solution isn't legal, but I still think it's bad that we have a massive media apparatus that can wipe out any voices it disagrees with, and which is fairly eager to use that against people like me.
I see some hope in federated systems, and, for that matter, old-school forums that have survived. Usenet still sputters along, but it's not what it was before spammers ruined it.
Harmless pranks from the 4chan crowd morphed into harassment campaigns like Gamergate and Pizzagate, then to 1/6 [edit: the storming of the US Capitol].
Anyone disingenuously complaining that their "freedom of speech" is under attack because they or their hero got booted off Facebook, Twitter, or some small forum, needs to learn to distinguish between private website operators and the government.