Earlier quoted context omitted.
Knuth wrote TeX as a labor of love. The surest way to kill everything good about it would be a few million dollars, and a team, and to turn it into fucking Google Docs for science. Ask Knuth to name one person who has the clearest vision for the future of TeX, and give that person a stipend to work on it for the next ten years, or for life, and you might actually do some good.
If I had a few million dollars budget for improving latex, I'd spend 90% of it UX research. What are people using it for? What are the biggest pain points? Which easy wins are there? Then try to modify it as little as possible while improving things.
And add better support for concepts like page numbers, page headers, page footers, which while theoretically supported by HTML and CSS, aren't well supported in practice.
Given that many people use Python now for scientific purposes, and it's a straightforward language, to add extensibility to this Latex replacement, maybe just use Jinja templates and Python packages.