PLOS Biology and PLOS Computational Biology are pretty well-regarded (the others are outside of my field).

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. "

It's "not p2p", it's just used like p2p. A lot of papers on arxiv nowadays are "preprints" that will only ever get "printed" on someone's office laser.

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".