The article is also from 2023.

It's funny to see how topics on reddit (https://l.opnxng.com/r/Unexpected/comments/1jvhcme posted 2 days ago), 9gag (https://9gag.com/gag/aW4vpKd posted 1 day ago) and HN (posted today) are always connected.

It reminds me of Cory docotorow's comment of something like 'there are 5 social media sites and everything is just copied from one another'

HN isn't immune either, given that karma provides 'rights to punish views and accounts' (downvoting). And it makes a great strategy to make a whole lot of socks with 520 karma, and selectively kill comments and stories you don't want.

I’m sure sock puppets and voting rings play a role, but “this link was interesting to a bunch of people on sites with some overlap in interests and demographics” seems a simpler and better explanation.