Ha, I had the same thought a while back along a slightly different vector (legal-adjacent technical writing). I ended up writing a blog post of my wishlist of features Word has that static site generators like Hugo don't appear to, yet. [1]
I think there's a lot of money to be made in this arena, especially given that LLMs are much easier to integrate with plain text files than with Word documents.
Much (but not all) of what you are looking for exists in the reStructuredText [1] space. Sphinx [2] is an SSG focused on technical writing about software that you may find worth exploring.
Also, the scientific text community has been pushing MyST [3] which is an attempt to take some of the best ideas of reStructuredText and reapply them to Markdown-style syntax as a baseline. The MyST tools are a lot more recent and don't have the maturity just yet of Sphinx (including the larger ecosystem such as SaaS hosts like readthedocs).
I think there's a lot of money to be made in this arena, especially given that LLMs are much easier to integrate with plain text files than with Word documents.
[1]: https://hiandrewquinn.github.io/til-site/posts/things-word-h...