If that was true we would not have any physics journals and many math journals. We'd just have people peer reviewing arXiv. Peer review is a lot more complicated than people think to find the right reviewers, minimize conflicts of interest, prodding reviewers, reviewing their reports. Also having editors read submissions first to see if it is even worth sending to peer review. This costs money and is not free. And it is why we have not seen a free model of this supplant journals.
This could be done not for profit or government funded (disclosure I work for a non-profit journal publisher) almost none of the expenses of publication are taking in a PDF, archiving it and paywalling it. The expenses are in review, curation and copy editing. For us this expense is millions of dollars a year and is public information.
We already have a free tier of publication in repositories like arXiv. There is still value in curation, selection and facilitating peer review and that cost is non zero.
The PhD scientists we have reviewing your papers, dealing with correspondence and selecting referees for further review are indeed not working for free. If there were a lot of people that wanted to spend a lot of time a day doing that we would not have to pay publishers for anything.
I have been a reviewer at Elsevier, Science and many of this journals for a better of the decade. I personally know the editors of many journals including IEEE, ACM, Elsevier, Science etc. They don't get paid for their time. So yeah, the scientists voluntarily review for free. Most journals only archive and index, they do not do anything more than it.
I do not know the case of every editor for all journals. Just sharing my direct knowledge as an employee of a large not for profit society. We did indeed pre pandemic have ~100 editors coming in the office not for free. THey now work remote not for free along with others around the world that are paid.
Not you but just in general sometimes HN is hard if you post an observation or direct experience that is not in the hivemind. You get downvoted for things even though they are well reasoned and true. I personally don't care if journals get disrupted there are indeed a lot of problems. I work in tech, I will have another job tomorrow. I was just making the point that we don't just have free scientists doing work and then upload PDFs to the internet and charge for them. If that was the case we could have journals for a few hundred dollars a month rather than the 10s of millions we spend. I also too think we are honest, do good work, are thrifty, and provide a good service.
If you work for APS, then you ought to be aware that APS is quite exceptional if it pays editors for overseeing the peer-review process. I am fortunate to work in a field where our main journals are still issued by non-profit learned societies, not gigantic corporations like Elsevier, and still the only people who get paid are the proofreaders and typesetters – the editors and peer reviewers have to work for free.
IME, the publisher provides extremely limited support to the academics who do this work (filter/select papers, recruit reviewers, organize reviews, etc). The professors involved are generally doing it as a public service to their field. The publisher provides modest amount of support and support staff, totally out of proportion to what they then charge for access.
Publishers only archive and index. The rest is done for free by scientists.