What's the meaning of "flatlands of paper"

In the following paragraph, Edward Tufte speaks of "flatlands of paper." I don't understand its meaning:

Even though we navigate daily through a perceptual world of three dimensions and reason occasionally about higher dimensional arena with mathematical ease, the world portrayed on our information displays is caught up in the two-dimensionality of the flatlands of paper and video screen

It is a reference to Edwin Abbott's classic satirical novella Flatland. Tufte is saying although we live a real, three-dimensional world, we get most of our information in artificial, two-dimensional representations: paper and on-screen.

"flatland" - a region in which the land is predominantly flat —usually used in plural

"flatlands of paper" - a metaphor for books, newspapers and written information in general.