The main advantage of LaTeX is that the format is more-or-less transparent. I say "more or less" because last time I claimed it is transparent, someone showed m

The main advantage of LaTeX is that the format is more-or-less transparent. I say "more or less" because last time I claimed it is transparent, someone showed me their .tex files and sure I could not understand them, but by now this has been the only time I could not understand a .tex file (this was someone who used macros to decline nouns, among other things; it's not a common use case). In general, if you see a .tex and cannot compile it, you can look inside and get a good idea of what the file is about in 5 minutes; a bit more time and you can essentially read it by hand. I don't know of any other semi-popular text format except well-written html+css (which is insufficient for science) that supports this. The cleanest systems will go obsolete and become unsupported; if I want my writings to stay around for 200 years, my best bet is to write them in a format that does not strictly require any decoder. And LaTeX, as commonly practiced, is such a format.