There's no one book I'd take to a desert island, not even the Bible or Shakespeare. Perhaps a book on how to build a boat or raft. Ishmael is the book I buy 10 at a time and give away to all sorts of folks. I first read it at 14 years old and have read it many times since. It is a very beautifully written book.
Libraries are an honest deal.
Their costs are small, their value large. Anyone can walk in and benefit from books that educate, entertain and instruct. Technology now links the smallest collections with the largest in the world. Librarians are adept at interpreting collections for patrons' needs and searching outside sources when necessary. Historically, private monies built and maintained libraries.