Surprisingly difficult question. It feels obvious.
After a lot of thought, I conclude, for now, that all the little advantages (text size choices, no light needed, 900 books in a handbag, etc) makes it a lot more FUN to read.
Similar to when I was young and got a quality racing bike. Compared to my old heavy bike, distances felt cut down to nearly half of what they used to be. And it was just great fun zipping through the landscape.
But if you tried to tell that to me before I got it (and before I could afford it), I would have poo-poo'd it; "Yeah, it's 'More fun'. Zippidy. Big deal..."
But it is a big deal. If you have to do a one-hour task every day, and doing it one way it's slightly tiresome, and done another way it is fun, that makes a hell of a difference.