It really depends on how you're reading. I find that smartphones are actually more convenient to use for reading lying down in bed, and the screen works better

It really depends on how you're reading. I find that smartphones are actually more convenient to use for reading lying down in bed, and the screen works better at night too because with modern OLED ones you can use black background with very dim amber text for very comfortable low-light and no-light reading. OTOH eInk is the best option for outdoors reading for sure, and the multi-week battery life is very nice when travelling.