I used to use pandoc (with pandoc-flavored Markdown) for this, but it just couldn't handle layout properly, even with mixed LaTeX and Markdown in the same files.
I'm not overly fond of LaTeX, but it is the only tool that does what I want.
What's fascinating is that this situation has existed for decades. Alternatives have risen and [mostly] fallen, but LaTeX persists. For that reason an alternative would not only have to be better, but significantly better, for me to question someone's choice of LaTeX.
Disclaimer: I have been using LaTeX (mostly XeLaTeX) for over a decade for most of my writing, mathematical and non-mathematical, although nowadays I often do so via Markdown+pandoc. Also, at my last company we had to parse mathematical formulas typeset in LaTeX and understand their structure... it was a nightmare.