You could avoid being large — small, high-trust groups work perfectly fine without censorship.

You could add more moderation (aka censorship), both platform-wide and within communities. Reddit seems to be heading in that direction.

You could avoid being a platform. Some sites are inherently platforms, but does every site need comments?

Or you could genetically engineer humanity into a kinder, better species. This would also be the way to make anarcho-communism work — the economic system with the greatest freedoms, but also the most susceptible to bad actors. The Culture series shows you a glimpse of what this future could be.