As a DARPA project, the early internet was populated almost exclusively by Americans for quite a long time. It grew rapidly, but I suspect that you're thinking about the culture that was steeped in almost everybody you talked to being an American.

Americans have a philosophy of the freedom of speech grounded in the principles of the First Amendment. Those principles are not universally shared, and indeed, even amongst the liberal nations the American take on the topic is pretty liberal (contrast the way, say, speech overtly supporting fascism is treated in Germany vs. the relatively new and controversial hate speech laws in the US, or the principles of affirmative defense for defamation in the US not shared by the UK, or the Refused Classification category for videogames in Australia, or the fact that the law of against "publication or utterance of blasphemous matter" was repealed in Ireland in 2020).

As the average internet user grows to resemble more the average human than the average American human, regression to the international mean on freedom of information is to be anticipated.