[conan50]

I think what has happened is that phones and tablets have vastly improved--better screens (bigger screens for phones), better-faster processors, more ram, newer operating systems with more features, and in many cases much lower prices than a few years ago.
E-ink on the other hand is stuck in three year old technology for the basic devices, and worse, have lost features in many instances like audio, 3G, physical page turn buttons, having lower battery life and lower storage on some base units. And the high end e-ink units cost as much as nice tablets. Also other hoped for e-ink technology improvements never arrived.