Copyright law has damaged global culture. Who benefits when the copyright to Winnie-the-Pooh takes almost 100 years to expire? Only the companies who sell licensed merchandise. Think about how many fan works we’ll never see because we bizarrely decided to grant creators a monopoly on whatever they create, even if the work enters the public mythology like with Star Wars or Lord of the Rings. The people of the country…
Do you think we should have shorter time spans? How short? Should star wars be public domain? Harry Potter? It's not an easy answer. Not everything is a hit right away... Some things like Song ofnIce and Fire only became hits decades later.
Actually, don’t even listen to me. In 2007, an economist named Rufus Pollock did research to determine the ‘optimal’ copyright duration to answer this question using empirically-estimable parameters and arrived at an optimum of 15 years.[0]
It is important to keep in mind that (1) copyright was supposed to promote the creation of new works, and so allowing creators to make a single hit and collect royalties until the end of time is not its purpose (at least in the United States), and (2) just because something is in the public domain doesn’t mean that the creator is now unable to make money from it.
Taking your example of the Song of Ice and Fire: if its copyright had expired before it exploded in popularity, George R.R. Martin would still be able to make money consulting for the TV adaptation. He would be able to make money giving talks and appearing at conventions. He would certainly increase the number of people giving him money on Patreon and sales of his contemporaneous books still under copyright would go up. He could cash in by quickly preparing some bonus content related to the book that is under copyright and sell it alone or as a bundle. He could do a fresh run of printed copies and tout their superior physical quality versus other copies on the market.
[0] https://rufuspollock.com/papers/optimal_copyright_term_talk_...