We often think of book pages as closed units, and of web pages as open;. of the printed medium as enclosed, and the digital form as free. And we prefer the open and the free, of course.
Openness also means dissipation. Hyperlinks can take you back and forth, but they usually take you away and forget to bring you back. The mainstream flows into so many sidestreams (of consciousness) than the volume is quickly drained into a valley of rivulets. Scrolling through continuous text as opposed to reading one page at a time is known to have a negative impact on attention and working-memory, as several studies have shown. When we scroll, we don’t tend to stop, and when we don’t stop, we don’t stop to reflect.
The ancient scrolls were great space-savers, but they made searching a pain. Searching is about going in depth, identifying the previously-unknown unit and carefully considering its relevance for the query at hand. When the codex (bound book) replaced the scroll (not completely, see the English administrative rolls, still extant), openness suffered a blow and the reference book came of age.