Yeah, I can't AB test against a world without copyright at all, but I think there's sufficient evidence to believe that a lot of stuff would never have gotten done without copyright to ensure it could be done gainfully.

The importance of striking a balance between incentivising creation and enriching culture was why the original copyright term was dramatically shorter. The modern term of owners life + 80 years or whatever it is, is clearly ridiculous. 20 years before entering public domain seems pretty reasonable.

There's unfortunately also some pressure against people using legitimate public domain works. E.g. youtubers getting copyright strikes for playing public domain music because it's too similar to a specific copyrighted recording.