I understand that with loads of comments you're more selective to who you reply.
But I think especially right now, when there are already less comments on posts, replying (to keep commenters motivated) is almost crucial. Also because the upvotes on comments are worth less (which btw could also be a reason for this less commenting).
P.s. I guess by now it'll be clear that my words are by no means a complaint, but more constructive criticism.