Is the idea of the open marketplace of ideas outdated?
Yes, it is. We ran this experiment with 8chan already. I consider Frederick Brennans opinion on internet moderation pretty well-tested by reality, unlike the 'free speech absolutists' I meet. Musk is a classic poster boy for that mindset and the instant he was given power his convictions really amounted to 'hide the stuff I don't like, boost the stuff I do'. So I think we should all be suspicious of people who claim this at this point.
8chan exists, as do lots of deeper, darker unmoderated boards. If they are superior, why aren't the majority of people there? Why are they almost universally despised and shamed?
Has humanity really developed into a situation where words and thoughts are more hurtful than sticks and stones?
No, humanity lives in reality where thoughts lead to actions and pretending like there's a firewall between the two is unrealistic. 8chan is routinely linked to mass shootings, and NOT JUST IN THE USA