Law apply to everybody on the territory relevant for its jurisdiction. Regardless of whether you use public services and benefit from its administration, you are expected to obey to it. If you don’t use a private service, you don’t have obey to their term of service, and law might even grants you ability to forbid private companies to exploit data related to you in their services.

The real problem here is not some private services chose what is or what is not available in their services. The core issue is their monopolistic position on information infrastructure. To some degree, people are responsible for not using decentralizing services, and for that, shame on people. On the other hand, when people are not educated to actively defend themselves against mass manipulation, it’s no wonder they end up trapped in that kind of "free" services. Of course, any form of political power that is not based on maximizing people auto-determination will precisely want easily manipulable people.

Neither these private companies nor political parties that now fake to be outraged by censure of opinion want auto-determined people able to share anything that might look like a menace to the centralized institutions they have in their hands.

That was my point. Free speech is not absolute. It has limitations everywhere. I think people have conflated three problems - 1) Tech monopoly on the internet and 2) Whether free speech is absolute and 3) Does free speech apply to tech companies. In a vacuum, there are different solutions for each. For example, you would break up tech monopoly, but that has nothing to do with free speech. But rather because it prevents competition. For free speech and its applicability, it is ok to legislate and define what it is, like Germany does. But I don't really hear a call for that

Personally I think such massive changes in society should not be down to either private company tyranny nor tyranny of the majority in a "democratically approved" why, i.e 50.000009% "ruling" over 49.999991% of the people.

In the US to undue the 1st amendment it would take not only a super majority of both houses congress, but then it would take 3/4 of all state legislatures to ratify the change. This is far more stringent of a requirement than is simply majority.

Republican forms of government, ones with lots distributed power, are far far far better than democracies