I will blame overlong copyright term lengths. 70 years after authors death or 95 years after publication, allowing most recent work to enter the commons effectively after a century, or more, from now [0].
[0] https://en.wikipedia.org/wiki/Copyright_law_of_the_United_St...
This is the rare case when Europe is even worse. Metropolis, the 1927 Fritz Lang film, is out of copyright in the United States but will still be in copyright in Germany until 2047: 120 fucking years.
It’s preposterous, and offensive to anyone’s intelligence to claim that this is about incentivizing production; does anyone seriously believe there is a potential artist out there who would avoid making their magnum opus if it could only be under copyright for 119 years?