3000 robots shouting into the void.
That being said, the next one is genuinely impressive: https://lemmings.world/post/405439
Impressive enough to cause performance issues in Jerboa!
(I'm not trying to be negative here, that's just what I sound like)
I don't think you can count the sites that just mirror Reddit comments.
Searching on lemmy.ml shows the top being several !news@hexbear.net megathreads with comments in the thousands, then that !asklemmy@lemmy.ml post you highlighted, more !news@hexbear.net threads, then a !meta@lemm.ee megathread about Hexbear's federation. I guess we can see who comments the most.
I liked this !imageai@sh.itjust.works post Your username is the prompt, what did you get? which has 1618 comments.
That's a cool one! I also just wanted to share the asklemmy post so people can read it.
And I agree about not counting them. Just takes some time to block them all! Plus I found it funny that it has almost 3K comments paired with only a single upvote from the OP :p
edit: Oh I guess someone downvoted it since hehe