At least for me, the "fluff" ends up being quite practical. I often remember stuff by thinking back to where I saw it in the book. With a physical book, my brain associates content with where I read it on the page (left vs right), how far into the book it was (judging by the depth of the pages), and what the book looked/felt like and weighed. All of this lets me recall information more easily, because the physical sensations jog my memory. Maybe I don't remember the proof of some theorem right away, but then I remember it was on the right page, towards the end of the book, and then for whatever reason it comes back to me.

Perhaps I'm weird in this sense but I know a couple people who remember stuff similarly. It matters more for textbooks or academic literature where I'm trying to recall specific information; with novels it's not as necessary.

Not outsourcing one's semantic network to Google and Amazon seems highly practical, unless one is a drone.