Not sure how lemmy compares but it isn’t unusual for user generated content online to follow a 1:9:90 distribution of posters, commenters, and lurkers. Just look a the number of upvotes a post gets compared to the number of comments it has and you can tell that most people who vote dont also comment.

I rarely comment because internet discussions tend towards arguments. I usually just upvote comments that already say what I was going to comment anyways.