But it's not. Workplace documents are different from novels. People use documents. Even with paper documents, people want to jump in to just the information that they need, grab that information, and jump back out of the document. That difference may be disappearing with high resolution monitors, although we do not yet have definitive research with a relevant task, such as reading and understanding.
Many people still find reading from the screen for extended periods to be difficult and tiring.
If they are looking for a specific answer, they don't want to see a whole book on line. A single printed book often covers many disparate topics because in print it is easier to publish and distribute one large document than many small ones. The document format you had on paper is usually not the right one for your users on the Web. The users of those materials may want to print out entire articles and read them from beginning to end away from the computer. In that case, of course, putting the printed materials online in easily printable form is valuable.