I'm 54 and have been reading for over a half century now. I'm very accustomed to having page numbers as I read printed books for all of those years. The Kindles came out and two things made them quite different from the experience of reading a printed book.

One, they used locations rather than page numbers. It is not a big issue, but if you have grown accustomed to half of a century worth of seeing page numbers, then you notice the lack of them. And locations, though logical, still don't easily register in peoples minds the way page numbers do. So let us call this one a question of TRADITION.

Two, a printed book gives you immediate, visual feedback as to where you are within the book. A printed book is of course 3 dimensional whereas a Kindle has only a 2 dimensional reading plane (screen). You can easily see how large the stack of pages is on the left side as opposed to the right side of the center of the open, printed book. You eyes easily gauge approximately how for into the book you currently are. This is because printed books have depth whereas Kindle books do not. Once again this is more TRADITION than anything, but I like having that quick glance gauge. The older Kindles gave us the digital equivalent of depth by providing a progress bar. I'm thinking this progress bar concept was copied from computer interfaces, but regardless it gives you a quick glance gauge to see how far along you are within a book. The older Kindles even showed divisions (as in chapters/section) along the progress bar so you could even see approximately how close you were to the beginning of the next section/chapter. Even printed books rarely have that gauge.