[owlninja]

I believe the majority of it is, what do you have that says otherwise?

[shinycode]

Some people commented here on HN they created bots that played along as humans by answering coherent comments on random posts to train their AI with the ability to argue and dig into the discussion. There’s a thin line between this and fake posts

[mattigames]

It seems they were talking about reddit content before 2023

[squeaky-clean]

It's been very noticeable since at least the 2016 election.

[memefrog]

Large amounts of it might be written by humans, but they're humans that are being paid to promote products and brands. It's an open secret.