I don't know precisely what they do--and I almost wish they wouldn't--but many journals still do some kind of layout work and copy-editing to cram it into the journal's house style.

It's often not very good: an overzealous typesetter replaced every single italic p (as in "p < 0.05") with a musical quarter-note. Still, some of that money must be going somewhere.

That said, I would actually love a journal that offered (good) copy/line editing of accepted papers so that the science is presented as clearly as possible. I suspect this would work out well for the authors and the journal. At the margin, easier to read => more cites. However, very few journals compete on "author-friendliness". It's all impact factor this and metrics that.

I am basing my opinions on work at a small/medium publisher that had well know material considered essential in a variety of fields-- they were pretty high quality. This was a while back, though I know people that publish in fairly reputable places.

They did and do this sort of editing, so it may be, sometimes, a matter of journal quality. I don't anything gets into JAMA without that level of editing.

Anyway, that's what my opinions in this thread have been based on, but maybe I'm exhibiting selection bias by having experience primarily with a higher quality publisher.

I would like to think I publish pretty well for my field and access to resources (PNAS, Neuron, etc), but none of those journals have offered anything beyond word-level editing (e.g., change sec to s; replace `subjects` with `participants`) to match the house style.

I certainly didn't get any suggestions aimed at improving the readability of the text; those mostly came from coauthors and colleagues before submission, with a few more things flagged, in passing, by peer reviewers.

That's on the biology side of things. For ML, it's basically "Here's the doc class! Good luck!"

Here's a paywalled clinical journal article about the hazards of poor typesetting!

A nomogram got futzed around and, well, the ruler-only, no-calculator required, calculations were now wrong.

"A set of trial calculations indicate that the nomogram of Burton et al is accurate, but a realignment of Burton’s nomogram (for greater symmetry?) in the Clinical Nutrition text resulted in a nomogram with considerable inaccuracy."

https://doi.org/10.1093/ajcn/54.3.435

You're right: Journals don't do those things, publishers do. Even PloS, open access & no subscription fees, has nearly 500 employees and an editorial group for each area, which are paid. Search up their salaries, you'll fine them. (They charge about $2000 per submission to the authors. Picking at random, the most recent issue of one of them had 80 articles, or $160,000)

Or look at the editing that Elife professional editors perform in addition to other peer reviewers: detailed feedback on the manuscript for the authors, including requests for revisions and suggestions for improvement." detailed feedback on the manuscript for the authors, including requests for revisions and suggestions for improvement

Maybe poor quality journals don't do this sort of thing, I'm not familiar with them & their economic models.