First, the United States method of copyright WAS the best.
Economic success is a measurable part of the equation.
There is very little PD footage after 1963. The property's usefulness to the copyright holder is now in question unless the holder fulfills the additional requirements. This, versus the notion that the generational terms are the copyright term. In the above scenario, the balance of copyright seems to be leaning far towards the public. If the copyright holder does not see significant value in the property, the copyright is not renewed, and it goes to the public.