I'm nearing the 0.1 release of Burro, a new typesetting language intended specifically for text-heavy documents. (If you've used the mom macro set for groff, it will seem very familiar to you. I like to describe Burro as a spiritual successor to mom.) The goal is to eventually have all the power of TeX with a much more pleasant syntax (after all, a typesetting language should be easy to type!).
The goal of the 0.1 release is to have a strong engine for setting English text, and I'm pretty much there. The main focus of 0.2 will be the macro system and beginning work on internationalization.
I started Burro in October 2018 and took a four year break (yay side projects!). I came back to it early this year and have been working on it pretty consistently ever since. It's exciting to have gotten this far!
Website: https://burro.sh
Typst might be powerful enough that Burro's "explicit layout" desire could be implemented as a library in it.