This would be a horrible nightmare. LaTeX is an atrocious mess that deserves to die. Source: personal experience trying to build a decent programmatic table creator for LaTeX.
Hence the (La) part being optional. Normal TeX isn't bad at all, from what I can see.
Most of the publishing industry still uses .docx, some of the more advanced publishers have moved over to ASCIIDoc - personally I think Markdown is the easiest to use for a big project (having written and published a technical book prior).
Except for scientific publishing, where LaTeX is king.
Most people I know use org mode with inline latex for stuff that needs to be latex.