Books only require the efforts of one person for a relatively short period of time and only a shoestring budget and as a result there's an unfathomable number of books to choose from, and the technology required to manufacture books is so simple that any number of large companies deciding to opt out of paper books is not going to stop them from being made. Even if major publishers and stores stop selling physical books, these factors mean that nothing short of literally outlawing paper books could make them a thing of the past.