Pollen is just a very extensible and composable slate for you to compose content. Under the hood, Pollen may be equivalent to the Scribble language without the fixed export structures and styles.

That the outputs look very good may be correlated with the author and other prominent users caring for typography and web delivery.

As-is, my impression is that generation of multiple pages seems slower than scribble/manual, but the community has been exploring use of databases to speed up caches. In this respect, I've been eyeing the work of this member in particular: https://github.com/otherjoel

All this speaks very good of the seemingly limitless flexibility of the Racket ecosystem.