Unlike other kinds of content most books ever written are out of copyright and completely free today. Publishers and distributors, however, have every incentive in the world to keep charging you for them. Efforts like Project Gutenberg and Calibre are going a long way towards taking back control from Amazon & co. for things that shouldn't be owned and controlled by them in the first place.
Of course calibre has legal uses too. Certainly books like War and Peace and other classics are still relevant today, however they are the exception, rather than the rule.
