Seems like, in 2026, we can have direct publishing without the need of these services? Is it the infra, like query tools and such, that prevent a migration away?
edit: I'm not going to reply to every comment, but thank you all, helps paint the picture a bit better for me!
If you don't care about how science street cred works, nothing stops you from just throwing your papers up on arxiv. But then you get no publishing rep. And no visibility either. A big name journal in a given field gets eyes on your paper by default - but in the pits of arxiv, if you don't put your work out there yourself in the circles, no one will see it.
Then you had promising projects like Plos, but they sold themselves. They turned into a joke: open access and good IF, but high fees for the author, thus becoming a quick way to get a sub-par paper published "for the points" if your lab can pay the fee. Pay to win, using a gaming term. If you know you have a good paper, you publish on any other (closed) journal with similar IF but cheaper.
The authors who put them up there didn't even plan on publishing in a journal. They just throw their work out there - no peer review, no nothing. Post the link on Twitter and maybe someone in the field will see it and find it useful.
This is especially true in fast-moving and highly applied fields like ML - the fields that are less "big science gang" and more "high intensity corporate R&D warzone".
PLOS One does publish pretty much anything, but that was always meant to be the point: "here's some data, make of it what you will. "
Hosting pdfs + paying out reviewers could be covered by donations.
My mental model is a non-print journal, so there are very few "publishing" costs, but the overall administration of things, from the tech side to the typical scientific paper processing workflow, is not a long term task for volunteers (I suspect).
Reviewers are not usually paid.
Any replacement system needs to somehow serve as a token for people who can't/won't actually read your papers.
It's easy for anyone to publish papers online, but it's very difficult for a journal to build credibility and reputation. If you publish in some random journal no one has ever heard of, everyone will assume your paper couldn't get through peer review at a "real" journal.
That's why the established journals exist.
There are a lot of researchers writing papers. In many fields it isn't possible to read them all, so you need someone to make a selection of what is useful. Get into Nature any "everyone" will read your paper because it is important. However if you fail that you only get into a small niche publication - the only people who will read your paper are people who search it out - likely because they are in that tiny niche (and have personally met you to discuss this niche at a conference). There are even lower grades up publications which nobody reads, but in theory someone could find it in a search.
What physics papers should a chemist read? If you are a physicist you should be reading more papers, but there are still too many to read them all so you need a selection, but that selection should bias to others working on similar problems to you. The same applies for every other field: you can't know everything so you need someone to apply a selection to tell you what is important for you to know.