As LCD cannot do what EInk does (and vice versa) it seems illogical to assume that either will totally drive out the other.
Also, while I find the battery life of an LCD device is often perfectly acceptable for a single reading session, where it really falls down is if one puts the device down and doesn't get back to reading for a day or two. That's where an EInk device shines and an LCD goes flat.
They do different things well - they complement each other.
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