I think Typst looks really interesting for some scenarios, but inadequate for others.
I like RST a lot for Python documentation, because of all the directives for types, admonitions, and lots of domain-specific stuff. I wouldn't use RST if I'm writing a book, or a research paper.
In the same way, Typst looks like a great candidate for those last examples, but is likely unsuitable for documenting a library written in Python.
typst is great, but there are many many steps between “markdown isn’t sufficient” and reaching for typst.
1. typst only really has pdf output at the moment
2. so much less tooling available (linters, site builders, converters etc)
3. much less of a markup format, extremely tightly coupled to a specific tool (typst compiler)
again, love typst, but it has (atm) so much fewer applications