Why isn't there a foldable e-ink book reader?
It has been 15 years since Amazon introduced the Kindle and we're still stuck with a single page tablet. Why isn't there a folding or hinged screen ebook reader, so that we can read books the way we've read them for ages?
Portability is probably a big thing, the fact that Kindles are advertised as being significantly thinner than a paper book. There is also just a large lack of innovation in that area, due to the fact that Kindles sell no matter what. Very few improvements are made but new Kindles always perform well.
Perhaps it could be a KickStarter project? As long as it allows you to read all current eBook formats. I wouldn't mind if it could also be used as a tablet.
There are hinged paper versions which still work well.
What would be the point? Books have the shape they do because paper is two-sided, and they are optimized for information density. There's no inherent value to seeing one page next to another, and even less in having a fold.