Here's another thought: if there is a type of paper (I'll call it a "codex" just to have a label for it) that can be shaped like origami into whatever format you like, with whatever content you like downloaded onto it, it could expand beyond the traditional uses of books.
You could shape it into a poster size and download the Mona Lisa to display on your wall for a while, for instance. It should also be very cheap, so you could hand it out as a flyer and not expect it back. (However the person you give it to could also use it for their own purposes.)
I also appreciate the aesthetics of a book cover and nice paper. That could be re-created by the codex as well. If you can change the shape of the paper to make it a poster, newspaper, coffee table book, paperback, flyer or notebook, you could also have it display a beautiful cover and change the texture of the paper itself.
There's no reason to focus on the negative. The expansion of media into the digital realm means that more niche tastes will be catered to, not discarded. The era of scarcity-driven mass media is coming to a close. People who don't care about book cover and paper aesthetics will get what they want. People who do care will also get what they want. Even tastes that haven't been dreamt of yet (artwork on demand) will be catered to.