> It's really surprising that this part is not more common.

I think it is because of low Emacs adoption and other editors not having enough support.

The problem with polyglot notebook workflow is probably, that you can only use it well for small data, or at least not big data, because who wants to have a million lines of output suddenly appear in the buffer, only to then read them as input for the next language ... That would be a tremendous amount of computational overhead. And if we didn't have that, we would need a way to pass a proper value from one language to the other.

What I also like is, that you can define code blocks that are used as formulas for spreadsheets (tables) inside the document. That's quite powerful too.

> (Even more niche is the noweb syntax for proper "literate programming". Which is mostly discussed about how awful it is to use in practice?)

I don't find it very awful to use. I have used that for working through computer programming books and it was fabulous.