> I’m sure you’re right for individual authors who are driven by a creative spark, but for, say, movies made by large studios, the length of copyright is directly tied to the value of the movie as an asset.

That would be fine, if the studios didn't want to have it both ways. They want to retain full copyright control over their "asset", but they also use Hollywood Accounting [1] to both avoid paying taxes and cheat contributors that have profit-sharing agreements.

If studios declare that they made a loss on producing and releasing something to get a tax break, the copyright term for that work should be reduced to 10 years tops.

[1] https://en.wikipedia.org/wiki/Hollywood_accounting

Next, they'd switch to from Hollywood Accounting to Oilfield Accounting. Oh that wellhead is actually owned by this other company over there, we just purchased their product at a fair market rate while they were still in business, but now it seems that other company is going bankrupt and cannot do the environmental cleanup to even seal the wellhead, much less remove it.