[academia_hack]

They don't even copy and paste the text! At least in my experience, once done with peer-review I spend a few hours wrestling with the "print ready" LaTeX template provided by the publisher to get my paper and tables to render correctly. Often they'll have an out of date LaTeX compiler or something else in the pipeline, so there's actually quite a lot of unpaid labor involved in getting a paper into a PDF that a journal will host.

The main services they supply are basically document hosting and search functionality. Both at extortionate rates.

[nvm0n2]

The main service they supply is a form of pseudo-price discovery like h indexes and more vaguely quantified reputation, needed because it's not a market economy.

[SonOfLilit]

I admit this is not a part of my comment I expected to have refuted