I just cannot read e-books efficiently, when it comes to casual reading I would rather not look at a screen as it's hard on my eyes and somehow a bit distracting (I read fanfiction online sometimes but only a bit at a time), and when it comes to non fiction and university reading I hate not being able to flip back and forth or easily skim for relevant information. This might all be personal though, everyone should go with what's easiest for them if they want to read more.
I don't however like the idea of not truly owning a book... I'd always be worried that Amazon or whoever could rescind ownership of my entire bookshelf if I didn't have physical copies. And also fewer physical books in circulation would make it harder to find second hand copies