I think you are missing the point of using an e-ink device… I don’t think anyone would use one because of “how powerful” it is.

I don’t want to read for hours on end on my phone or computer. With this, I can turn backlight off and use a lamp, like a normal book. Better for my eyes and relaxing.

Also, having dedicated devices for certain activities will change how you interact with them when using them. If I read a book on my computer I am tempted to look things up, get some work done or play a game. This is just for leisurely reading, and so when I pick it up that is what I do with it.

If you read a lot (books, not documentation which requires looking things up) then it really is a lot better for your eyes and a better experience to use e-ink.