It seems to be more prevalent on lemmy

I’ve noticed this with the two largest Lemmy instances – .ml and .world.

it’s still mildly-infuriating to see obviously innocuous/irreverent posts/comments being dogpiled

I think early downvoters are just trying to induce others to follow them because they’re assholes and have nothing better to do. Unfortunately, it’s pretty common with both Reddit and Lemmy.