We are still in an age when physical pages constitute "reading" and things on a screen constitutes "writing", regardless of PADDs, sorry, iPads and Kindles. Reading still equals paper.
It will change in time. E-published books and Kindles are popular among people over 65 I know because they can change the font size easily to accommodate deteriorating eyesight.
Give it ten years and a generation of elderly people who want changeable print size and a publishing industry who can accommodate that easily with e-books.