Copyright was invented to encourage the production of works of art and literature (not necessarily fine literature -- even pulp novels have their place in a society). Well, technically the original copyright law was intended as a form of censorship: it was a bribe from the British government to the book publishers guild, giving them a monopoly on books so long as they didn't publish anything that the government and church didn't like, and were vigorous in stomping hard on anybody who did. But putting that aside, modern copyright law was created with the motive to promote the useful arts and sciences. The intention is that since the creation of a work of art is of doubtful profitability, since an author could spend months or years creating a work only to have some other publisher copy it and make the profit, society as a whole is better off if we grant that author a limited monopoly on the publishing of said work. The good to society (more works of arts and sciences) was the intention, the author's profit, if any, merely the mechanism to get that good.
An admirable intention, but over the centuries, it has become corrupted by the involvement of corporate interests. Copyright law is now, de facto, treated as a method for the promotion of profit. The emphasis is on the copyright owner's profit, rather than the benefit to society. The historical record is unclear on whether copyright ever really did lead to more works being produced, but it seems clear to me that today copyright is a barrier to be overcome rather than a tool for the promotion of useful arts.
From New Zealand comes an example of how copyright law is used to reduce rather than increase the amount of useful arts available to society. Copyright law in New Zealand lasts for fifty years after the death of the author, and consequently Robert E. Howard's Conan The Barbarian stories are in the public domain. The New Zealand non-profit, all-volunteer website BrokenSea Audio produces audio dramas based on Howard's work.
Alas, the Conan stories are not in the public domain in the US, where the monopoly on Howard's work is owned by a corporation, and they see New Zealand's volunteer, non-profit Howard fan as a threat to their bottom line:
All Conan audio dramas and audio books produced by its volunteers have been removed from the website, and a major project — a production of Howard's only full length Conan novel, Hour Of The Dragon, which Mannering had adapted into a full cast audio drama script — has been cancelled.
We see this over and over again: copyright law being used to reduce the amount of useful arts produced, instead of increasing it.