In the early noughties I really believed that free speech online would work with just a very light moderation. We tried that approach with a rather small online community for an Italian political party where already all participants had pretty similar ideas.

What I learned the hard way (as hard as having light PSTD) in the course of 3 years is that just doesn't work. You only need a handful of motivated people who won't stop at anything to push their agenda and narrative to create an extremely toxic environment which only favors the best liars and the most unprincipled people.