Hello frens,
As a great opponent of any form of IP, I have been following the event of Disney’s Steamboat Willie entering the public domain with great amusement. The incidents where creators have been falsely demonetized on youtube for rightfully using this film is further underpinned by Disney’s decades-long shameless practices. The linked article sums it up quite well I think.
Copyright law in the U.S. used to be 19 years with an option to renew after that 19 and was that way until the early 1970s. That should be more than long enough for any copyright to last.