EInk doesn't have a backlight. So it's easy to see in glaring light. It's also not disruptive if so, you want to use it as a digital picture frame and you don't want light from the display bothering your eyes day and night.
EInk is a more peaceful display technology, and some people put a lot of value on that.
How is that a realistic feature? Who is losing power and being happy that they spent a few thousand more, nearly 40x, than a 36" photo quality print, just so the image can remain while their lights are off?
(and of course it is a lot easier to change than a printed photo)
I understand being eco friendly, but that’s an absurd, entirely negligible, justification.
I would claim the reflective display is the killer feature.