Meh there is some kind of artificial scarcity making e-ink screens expensive as far as I can tell, especially big ones. If e-readers are declining it’s because people are using their phones instead, just like small digital cameras have declined. Small e-readers just don’t have much to offer compared to phones.

I don’t know how the market in tablets is doing. But there are no affordable large e-readers (13" and up) as far as I can tell. I can’t predict whether such a thing would get traction if it existed, but I’d be interested.