I like that idea, the tricky thing is comments require more context. So if there were a way to make it as “top conversations” than just comments, I think it might have more success.
Most people are not aware that ranking for upvoting top comments is WAY easier than ranking for upvoting posts. To me that’s plenty of incentive already to engage with comments and a way for them to compete with posts.
Comments can be extremely detailed and valuable, but there is plenty of work in posts, especially those generally speaking with more sats & longer word counts.