I don't have any professional typesetting experience, just some adjacency from having done some work for a type foundry at one point, that gave me some insight into how much actually goes into it.

Most professionals use expensive professional software for it. Latex or pollen or other pure markup solutions only work for smallish documents, or digital ones. Once you're going to print, esp in different formats, you need to care about page imposition, aligning with folios & signatures, widows & orphans etc. Just generally the physical reality of paper leaking into your abstraction of "the book" in ways markup alone can't accommodate.