Keep in mind that the costs associated with free speech are currently visible and obvious, but (precisely because we have free speech) the costs of censorship are not. It is true that a free society will have more protests and unrest, sometimes violently, but that doesn't change the promise that a free country is less likely to have a multi-year civil war or government led genocide in a decade. Given that four people died at the Capitol and millions typically die in wars, that's a trade-off I'm willing to make. The argument for free speech typically doesn't claim it's better than an optimal world where only truthful and productive speech is possible, just that it's better than what you _actually get_ in practice if you attempt to only allow truthful speech, which is handing unchecked power to the people making that judgement.