Completely agree. While I'm usually against Government interference in private enterprise, these guys are too powerful and I think anti-trust legislation may well be in order. There is absolutely NO chance of competing platforms being offered. The've got the market locked down.
Additionally, you can't claim to simply be a platform (and as such not responsible for the content of posts) if you edit, or restrict what posts users can make. Now they have accepted responsibility for the content of posts as they remove some they deem inappropriate.