But we do. In many countries, and even in the US the history of what is and isn't a good trade off to limit speech is a long and still ongoing discourse.

Sure, the gov part seems easy, but then people call on FB to filter lies in political ads, and again people want laws to mandate social networks to do this, and so on.

What about shouting fire in a crowded theater? I've had lengthy debates about whether that should be allowed or not, and if we still "have" free speech if we disallow it.