I feel like we're on the cusp of being able to have a qualitatively better technical book using interactive media instead of page flipping, but to date this has not materialized. For casual introductions (i.e. browsing wikipedia) a phone or table is fine, but a technical book that seeks to lead the reader from basic understanding to deep knowledge remains tantalizingly out of reach for anything but a physical paper book.

Being able to rapidly backtrack and sidetrack seems to be the critical issue; paper allows you to do this so easily with a thumb or other improvised bookmark. Hypertext and forward/back navigation and tabs seems like it would be perfect for this, but it doesn't quite work.

Learning effectively from a technical book has to be like lazily reading a detective novel -- you have to be willing to look at the ending. You do this before you're in a place to understand it, and then build up that foundation to the point where it supports what the end goal is going to be. Maybe it's a question of having a writer who can make this idea a first-class one, by repetition and backtracking in a forward direction; effectively first presenting page 8, then 4, then 2, then 1, then 2, then 8, then 2, then 3, then 1, then 4, or some similar scheme to allow the reader to shore up their understanding, while allowing them to skim through parts that seem boring or are too confusing, with the knowledge that they'll have another chance to review the material, without having to manually backtrack.