This is not the same league, maybe not even the same sport.
Markdown is for convenient and quick "good enough" looking text editing. It is very good at what it is supposed to do, but the limitations are quite obvious.
Typst has its focus on editing scientific documents, something that Markdown was just not made for.
Typst texts are quite readable, the language has explicit support to make it as good as feasible (e.g. longer text parameters can be passed unquoted within a [] block, so it is still left readable). Plus you can abstract away more complex configs inside a function, and end up with `#myFunc [My normal unquoted text]`
But it is apples to oranges, you can properly format text to book editor capabilities with typst, while you can only do basic stuff with markdown.
Markdown is for convenient and quick "good enough" looking text editing. It is very good at what it is supposed to do, but the limitations are quite obvious.
Typst has its focus on editing scientific documents, something that Markdown was just not made for.