[exporectomy]

Regarding indigenous culture, I'm talking about how natives claim ownership of art styles because their ancestors created them and they use social pressure to stop others from copying them. See https://medium.com/the-omnivore/the-cultural-awareness-requi... for example.

For patents, it's important to ensure that ideas become available for everyone else to enjoy despite giving a monopoly to the inventor. That's because an invention may be the best way to do something and we would be worse off if we couldn't use it. Copyright, on the other hand, doesn't protect anything fundamentally important. It's just individual products of human creativity. If you want a cartoon animal, you can always create your own without having to build on Mickey Mouse. The protected ones don't really matter except that they've been pushed into popular culture and people have lapped them up. We could do our culture in a way that doesn't suck at the teat of industrial culture-generation factories like Disney if we didn't want the impediment of copyright.

So I don't think your argument about give and take is really convincing. We could even have infinite copyright and the world would get along fine. If some obnoxious copyright owner enforced their rights to strongly, somebody else could create an equivalent work that was just as good to replace it.

I don't think they'd do it without copyright though, as evidenced by the fact that almost nobody does. Even open source developers still use copyright to restrict distribution (GPL) and amature artists demand credit (CC-BY).