Re: post/comment quality, one thing I do suspect helps which I didn’t see anyone mention (and imo a potential upside of rate-limiting) is that age-old forum standard, lurking moar. I think it can actually be hugely valuable to spend awhile reading the historical and present discussion of a site and absorbing its norms of discourse before attempting to contribute; in particular, it’s useful for picking up illegible subtleties of phrasing and thought that distinguish quality from non-quality contributors, and for getting a sense of the shared context and background knowledge that users expect each other to have.
Re: post/comment quality, one thing I do suspect helps which I didn’t see anyone mention (and imo a potential upside of rate-limiting) is that age-old forum standard, lurking moar. I think it can actually be hugely valuable to spend awhile reading the historical and present discussion of a site and absorbing its norms of discourse before attempting to contribute; in particular, it’s useful for picking up illegible subtleties of phrasing and thought that distinguish quality from non-quality contributors, and for getting a sense of the shared context and background knowledge that users expect each other to have.