Not responsive enough when changing pages. Too much tech crammed in to ramp up the price of something essentially worth $15. Navigation is unintuitive, it's hard to get stuff on the device. Not all formats are supported by all readers and PDF support isn't what it should be. I can't turn pages with either my left or my right hand, no easy switching beween books and if you've got more books on there than the average person, like maybe 70, you're already screwed to find what you want to switch to reading at the moment quickly.
You probably have a blind spot for people that are not able to speak English and are working in conditions that are kept secret by design. Coincidentally I know someone in that situation who works on AI since at least two decades and who has kept radio silence since one decade on what he's working on exactly.
Lifetime is very misleading. I expect smartphones and apps to become obsolete over the next 40 years. Just like pretty much everything software from 40 years ago is obsolete now.