Which stages are you referring to? In my experiences in CS, publishing a _conference_ paper required:
- Writing the paper using a publisher-provided LaTeX documentclass (potentially a significant portion of publisher costs went into developing this style)
- Submitting the paper, via third-party conference management systems
- Review, performed for free by other researchers
- Responding to reviews, performed by me
- Submitting a camera-ready version of the paper. The checks were mostly performed automatically (PDF metadata, page size, fonts, text size, balanced last page, page limits, margins, etc.)
- Checking of the camera-ready paper (this seems like an actual menial task performed by someone on the publishing side, although I think that this was also contracted out)
- Assembling the proceedings PDF (again, I assume this was automated, with the menial task of checking TOCs, headers, and footers)
- Attending the conference itself (I assume the most money goes into this, renting the venue, organising AV teams, large amounts of co-ordination)
Things then get worse, because one specific publisher charges for intstitutional access, again for Gold OA (though Green OA is a free option), and then several hundred dollars for attending the conference.It seems to me that most of the menial tasks are already automated. A lot of the menial tasks are even contracted out. I have colleagues who go to great lengths to organise local seminar series, run workshops, Perhaps I am missing some, or some of these are much more involved than they appear on the surface.