I don't think you are right, here. At least from a factual "as is" legal standpoint but also from my moral standpoint ("what should be" / normative).

I am not sure which standpoint you are addressing.

The easiest standpoint to defend is the factual / descriptive "as is" legal standpoint:

Insults / defamations are legally not allowed in most countries.

False advertisement IS indeed an exception to free speech. See here [1].

But maybe you were not talking about descriptive claims but normative ones. This would be a very different discussion.

[1] = https://en.wikipedia.org/wiki/United_States_free_speech_exce...