I think it helps to distinguish different types of costs. If we're talking about general technical writing editing or assistance getting something latex-ified, that seems like the kind of thing that can be readily pushed back onto authors themselves. For example, the volunteer editor could easily tell an author: "the reviewers loved your work, but you need a technical editor to make this acceptable for publication: hire one, get it fixed up, and submit it in 2 weeks if you want it published". The same thing could be done for Latex help.

From an author's perspective, paying for a tech writer to help them edit would only need to be done if they're actually bad at writing, in which case it seems perfectly fair to have them spend a few hundred dollars paying a local editor to help get their work publishable. The net financial benefit to having another published paper on their CV is certainly worth far more than whatever a good tech writer would charge.