Say it were implemented in this world and you could say anything you like (written, spoken, signed whatever) to anyone who can hear/read/see it. What kind of problems could that create and are there any ways to resolve them without limiting that absolute free speech?
Could it even create unsolvable logical errors? E.g an omnipotent god can’t create a stone too heavy for itself to lift. Maybe there are similar things with absolute free speech.
The idea of free-speech-absolutism relies on a top-down model which only examines how a government or platform should regulate speech, while completely ignoring how free a space is depends as much on who participates as who controls.
Free speech is also dependent on the twin stupidities that a “market places of ideas” will produce good ideas, or that debate could possibly settle the most trivial issue.