I recently came across Typst. It’s a typesetting software under active development that is designed to be as powerful as LaTeX while being much easier to learn and use. Features Free and open-source. 22,000+ Github stars: https://github.com/typst/typst
The one dealbreaker for me in Typst is the current lack of locale-aware decimal separators. The rest of it is so good that I've donated a couple times.
Note that this is not only a cli and a (closed source) web editor, but also a library. So it's possible to embed a full typesetting library in your project, which is awesome. It's probably not on par with TeX yet, but you can already do an awful lot with it. Scripting it is really much, much easier than, say, LaTeX.