[Symbiote]

Those aren't books, they are presentation slides.

Using Powerpoint, for every slide the author chose (potentially) a different Powerpoint template (2×1 columns, 2×2 etc). They have complete freedom to "break" the structure, such as with callouts pointing to the "other" column, images going beyond the margins.

A automatic template removes this flexibility, but allows scripting or rebuilding the document with different text/data. That's the compromize.

Remark.js achieves some of the most basic parts of this, but would need some fiddling to add some CSS grid support and/or default templates: https://remarkjs.com/ (Except for being ugly, http://mobmad.github.io/js-tdd-erfaringer/ shows some possible structure with Remark.js).

[marvindanig]

Going by the strict definition of a book [1] a file, a webpage or a website isn’t a book either.

[1] https://en.m.wikipedia.org/wiki/Book

[airstrike]

I'm not so sure... I make them pretty much daily, and we print them and call them "books".

I'm not saying you shouldn't be able to tweak them manually, but there's got to be a more ergonomic language for drafting pages than literally dragging objects pixel by pixel, especially when most of the content comes in four forms: tables pasted in from Excel, charts pasted in from Excel, bullet lists and simple graphics around text like circles and squares