@skadi some troff preprocessors are like this but they are good imo. i like eqn more than the (La)TeX math stuff. pic also is nice.
@skadi troff is quite the rabbithole ;) i think you can typeset stuff as nice as with LaTeX, but it's rather arcane (just like TeX) in some places. getting the start of page/end of page traps right when writing a whole macro from scratch can be hard
i've been meaning to try out neatroff but haven't got to it.
some links:
https://www.troff.org/54.pdf
https://github.com/n-t-roff/heirloom-doctools
https://litcave.rudi.ir/neatroff.pdf
https://pjfichet.github.io/utroff/