"Free Speech" sounds great until you consider the real world. It's fine when anybody who wants to can stand on a soap box on the street corner and shout that the world is flat or that Jesus is coming back to smite the sinners.
It's a totally different thing in a world of calculated lies spread by highly-organized and well-funded propagandists, where conspiracy mongers make patently false claims of election fraud, where broadcasters with followings in six figures shout that the parents of murdered children are hoaxing the nation, where social media is used to organize an attempted overthrow of the government, etc., etc., etc.
If Elon Musk really does throw open the doors of Twitter to unmoderated free speech, the result will be the greatest destabilization of Democracy since Facebook. The prospect terrifies me.