Social media platforms have a TOS that binds them just as much as the user.
They can change their TOS at any time, and frequently do so, so no, they are not bound "just as much as the user."
It’s literally just a contract.
An unconscionable one, at best, considering the vast power disparity between a large social media site and any user. Clickthrough contracts should be banned outright. There's no way to negotiate. It's "my way or the highway."