If the objective was not spend on design software, why not use latex?
You can tell it was built from the ground up for books, and not scholarly publications. In that respect it’s actually closer to plain TeX.
It doesn’t try to be overly semantic because books are complex beasts, and there really is no useful-but-wrong simple model that doesn’t handicap you.
Like, not all books have chapters. Some have hundred of very short chapters, with multiple on a single page.
It’s also much more “batteries included”.
Basically; trying to do a book in LaTeX you end up fighting the defaults, and for some there are NO good reliable overrides.
Take a look at the manual (http://www.pragma-ade.nl/general/manuals/ma-cb-en.pdf) page 83 (numbered) 87 in the pdf. Imagine trying To the that in LaTeX.