(1) As I understand, the first modern copyright law was in 1700's Britain, which broke a printer monopoly and shifted control of works from publisher to author. It also meant that an author and their family would not starve while their work was still generating revenue for the publisher (who would have outright purchased and owned the work).

(2) This probably led to an proliferation of authors and new works, motivated by the prospect of royalties. In some cases, it enabled talented authors who would otherwise languish in obscurity. In other cases, it produced works of little value beyond revenue generation, by catering to whatever immediate demands for consumption that existed in the market.

(3) Obviously, intellectual pursuits, invention, creative writing, art all existed before the 1700. But as per (2), it probably greatly accelerated them, while also diluting quality.

(4) Mass production and distribution led to economies of scale, which meant a larger portion of the population now had access to such works.

If these four propositions are true, then it follows that abolishing (or severely curtailing) copyright will not outright eliminate any creative human output, but will probably mean that as a whole, humanity will take longer to produce the same output. Since the cost of production and distribution of digital media is now a negligible fraction of the cost of the creation process, this is unlikely to negatively impact availability.

Given that the world could probably afford to slow down a bit, perhaps some sort of curtailment of exclusive ownership of intellectual output might be a good thing.