Open Office exists as part of a free Java-based ecosystem. I couldn't say it is used in any serious publication workflows, but the components are there. Context is aimed at serious publishers, and has strong roots in educational (i.e., not academic) publishing.
Apples vs. oranges: the point of this subthread has been that I thought your statement But the underlying toolchain and language are past their expiration date. By far. and backing this up by talking about how hard "easy" things can be that turn out to not to be trivialities anywhere. Latex is not for casual users, but it is very much not past its expiration date for authors who are serious about typesetting. I'm not making excuses for Latex, nor am I unfairly bashing the alternatives.
I don't know a piece of free software that directly competes with LaTeX, the latter has been the de-facto standard for university papers and a small group of book-writers/enthusiasts for about 20 years.
However, pitting LaTeX against Word is about as meaningful as pitting Linux against Windows. You wouldn't excuse the thorny Linux desktop experience with the security track record of windows either - it'd be an apples vs oranges comparison.