I remember using T[sub]E[/sub]X
IMHO eBooks contain 3 distinct disciplines:
1) Word craft, the telling of the story
2) Artistic craft, The presentation of the words (mostly page layout and Style) and Illustrations
3) Typesetting (OK the term is mostly obsolete, but the results are the same) Transferring (coding) #1 using #2 to the output media format
What seems to be the thrust of this topic is to merge #2 and #3 into #1 and
have require the author to be good at all these tasks
No way am I any good at #1. I take an 'engineers' form of #2, Art: Functional (Solid, won't come apart

in a storm). I am a Mechanic type. Give me tools, and I will beat it into the shape specified in the
print (#2)
Self publishing is eliminating a lot of specialized crafts that
really make a book ready for market. In many cases it shows

.
The author needs a simple word processor to get the prose into a file with minimal markup (Bold, Italic) and allow copy editing.
The final results are then transferred to the coder who implements the Artistic instructions using available toolS for the job.
Somewhere we have gotten into a OSFA mentality. That is not the best way for an excellent product to get to market.