> Perhaps this is true in the field discussed in the essay, but in my field (a natural science) formatting is taken care of with latex stylesheets, so the effort of switching to another journal format usually amounts to changing a few lines.

That doesn't sound like the LaTeX I use. When you switch to another stylesheet, it often changes key dimensions such as page size and the number of columns. Then you have to reformat and possibly even redesign the figures, tables, equations, pseudocode, and so on. And it's quite likely that some packages you are using don't work properly with the new stylesheet, or even don't work at all, so you get some weird issues to debug.

But that's about the technical layout, which isn't the concern here, as the publisher is usually responsible for that. In biomedical fields, manuscripts are usually just Word documents with some basic formatting. The real issue is that different journals have different ideas about the length, content, and structure of the paper. When you switch to another journal, the paper itself often needs a major revision.