It isn't just big tech. It is that big tech decided to join fully with the rest of the power structure of the country: government, military, military industrial complex, media, law, health, education, etc... Those are the groups that actually run the country.

Now you have censorship by tech instead of just by government, propaganda by tech in addition to media, mandates by corporations and by government.

Before, tech just told government to compel them via law. Now, government works with tech and corporations to achieve governmental aims without writing laws. It is extrajudicial.

I don't think the USA is a democracy or it is less and less of a democracy.