How does a project with a built in package manger and a wide variety of packages lack "proper" extensibility?

Smaller community compared to LaTeX may lead to perceptions of lacking "proper" extensibility. For users needing niche or low-level typesetting capabilities, LaTeX’s mature and highly flexible system may still feel superior. Build-in package manager does not necessarily 100% guarantee full extensibility as in crazy Latex macros ;-) As I said, it is a young project and young company, it will grow in time.

Huh? Other than borowing some of the syntax, Typst is completely unrelated to markdown.

I had a feeling that it is similar to R markdown https://rmarkdown.rstudio.com R markdown is similar in capacity one can mix R language, but since syntax is Markdown they kept the name.

Yes, I meant, markdown syntax. Don't get me wrong, it is a nice project. I like how they adopt Rust.