A different perspective: If most of the speech is spam, hoaxes and lies, and if as a recipient, I have no meaninful way to detect those, then what value does the speech still have?

So if everyone can say whatever they want (which is a good thing), the recipients must have some tools at their disposal to verify whether someone should be listened to or not.

> If there are going to be limits to free speech, then who gets to set those limits and who enforces the limits?

Denying facts that are backed by the overwhelming majority of scientists would be a good candidate for a limit.