[otabdeveloper1]

EPUB can't cover this niche.

EPUB is basically just HTML in a zipfile, with all the ugly warts that HTML comes with. (Attempts to enforce "pixel-perfect" design, broken accessibility, ugly fonts forced on you, etc.)

EPUB is good for publishers, I guess, but a crappy ebook format.

FB2 is a different beast, it's an extremely minimal XML dialect that encodes only semantic information and nothing else. (Basically, tags for chapters/sections/headings/verse and that's about it. The extent of the formatting allowed is 'em' and 'b' tags.)

[darkpuma]

You can create your own clean minimalist epubs. None of that cruft is mandated, you can simply choose to not use any of it. Don't want to enforce a font? Don't specify one. Don't want a stylesheet? Don't put one in.

[robin_reala]

Presumably the problem here is restraint? I contribute to Standard Ebooks that uses EPUB3 as a core format. That’s based on HTML5.2 but our books have clean code, minimal styling and as good accessibility as we can make (we’ve had a couple of reviews of the core accessibility functionality and fixed any problems that came up).