Summary: Designing information for paper was largely about managing reference distance. On the Web, the reference distance is zero. A completely different set of design requirements apply.
Linear information design
Traditional information design thinking has always been linear. This is a consequence of the medium in which the vast majority of information was presented: paper.
Whether you roll it into a scroll or chop it up into pages and bind them into a book, paper is a linear medium. This presents a fundamental information design problem: some of the things you want to talk about in the real world have complex relationships that cannot be laid out in a single straight line.