They also benefit from having it freed from the constraints of paper itself, which cannot be on every researcher's desk-top, let alone be interlinked and navigable, even if everyone could afford it all. Note that this give-away story is being told from the author's perspective. There are benefits to users, including users who are practitioners rather than researchers, but I leave those to my readers to fill in. This account will be only from the research author's standpoint, because research impact is what it is all about, and that is the way to make sense of it. This point is still valid for the subset of biomedical research findings that could pose potential hazards to health, but the internet has now made the matter moot as far as journals are concerned.
Referees are a scarce resource, donating their valuable time for free.
There is no justification for squandering their time on a paper that has already been publicised without certification, or one that has already been certified and published by another journal. As to what will be read, and why, read on. Without that revenue, the research cannot be refereed or published at all . This fourth is the real rationale behind the Ingelfinger rule, and always has been. This was unavoidable, and hence justified, in the Gutenberg era, with its real costs.