the First Amendment (in the USA) is for protection from the government, not a private business

Increasingly becoming a distinction without a difference, as corporate and government interests become more and more intertwined.

(Suppose that the government politely asks Microsoft to ban all mention of "genocide" on Microsoft platforms, while making it very clear that it's completely optional, the government just asking for a favor, and it's not at all required, no penalty for failing to do so. Probably not even an official request. Just, say, the President rambling on social media about how it would be very "great again" if Microsoft did that. And Microsoft eagerly and voluntarily bans mention of "genocide". Later, the government allows Microsoft to make a big merger without worrying about anti-trust laws, and also gives them a significant tax break. Were first amendment rights violated?)