[hedora]

I think that was more true when less stuff was being produced, and the cost of keeping a copy was non-zero.

Those things stopped being true ~ 100 years ago, so now we end up with strange filters. For example, a large number of high-value film masters were lost in a single warehouse fire. (Arguably, shorter copyright terms would have prevented that, since distributors and fans would have had geographically distributed backups that the film studio had little financial incentive to maintain).

[JasonFruit]

Those are all good points.