It's worth noting that Wikipedia has been struggling with this issue for its entire lifetime, and ended up with a situation that people seem mostly unhappy with.

Yes. The English Wikipedia has a set of solutions for this that a lot of people are unhappy with. And then you look at what other wikis have tried to do, and you realize that their methods create even more serious problems and that if you tried to scale them to something of the size of the English Wikipedia disaster would ensue.

This is very much not an endorsement of Wikipedia approaches to the Less Wrong wiki. The purpose is very different, the community is much more narrow, and the total size is much smaller by many orders of magnitude.