It isn't clear to me that eink's underlying display technology isn't good at the interactive computing use case so much as the implementations aren't optimized for it. There could be a position where more power than an eink reader is used but still far less than traditional active displays since unchanged pixels aren't driven.

That's how I think about it too.

E-readers are vertically integrated devices: the hardware, software, UI, and refresh behavior are all tailored around reading. E-ink tablets like reMarkable are similar, but optimized around writing and annotation.

A traditional monitor is much more general-purpose, so it doesn't get the same kind of end-to-end optimization for the display medium. I think there's room for an in-between category: a more interactive e-ink device where both the hardware and software are designed around the strengths and limits of the panel.

There's some related work happening in this direction:

https://nlnet.nl/project/epd-wayland/