I've basically reported the same as you, and I too am (was?) very technical, trying to optimize and thinking that tablets were a super set of books.
The edge has a deep link to my memory, scanning with my thumb is more satisfying than having instant full text fuzzy search, which is paradoxical since search is more powerful.
I ended up thinking that we do need physical stimuli. A lot. And that our brain likes to reflect from physical to ideal, if we skip a step, we deprive/depress the system. It will work but less so than having a right blend of physical then ideal brain stimulation.
Also, books doesn't distract, a tablet is a book reader, and 120 other things, including a gateway to internet which is a known addiction now, so for some, there's always a slight effort to make when reading a book that is not already captivating enough or difficult at times. Dead trees are passive things, and you have no other option than to focus all your mind to them.