I reiterate -- multiple people have broken down the physical components of the device and calculated their total value as being only slightly under the selling price. If you really wish to believe that that does not constitute proof, go right ahead, but that's being silly.
If you just want to see that documentation for yourself, I don't have the links handy. But as I recall, the Wall Street Journal did the breakdown at least once.
You can continue to reiterate that "lots of people need a powerful eink device", but you are still wrong. Very few people need one, which is why only a handful of small manufacturers make them -- or at least, make a device that superficially resembles them. Manufacturers to whom it is
big business to see 500-1000 devices; in contrast, Amazon sells millions of Kindles.
And TBH, they too are catering as much to the large-screen readers who want to read with Android apps, as they are to the people who want a generic E-Ink tablet with blazing speed.
That is why even those devices make only a half-hearted attempt to be what you want them to be.