Whether or not “humans do it” isn’t relevant. You can walk around with a copyrighted song in your head. That is not copyright infringement. But if you take that song, create a digital copy, and distribute it for money, then you are violating someone’s copyright. Additionally, our legal system requires a balance of probabilities. It’s hard to prove that someone was influenced by another work unless the similarities are plainly obvious. The same does not apply to ML models where the training data and algorithm are knowable facts.
I challenge you to listen to 4 chords of awesome and tell me again about how every song is completely original. How does eragon exist when it's definitely ripped parts from star wars, etc...ai usually doesn't spit out a full plagiarism, but a loosely inspired work which is what most media we consume is.
A copyright in just Eragon would be incredibly thin, for the exact reasons you state. This criticism of copyright by people that have no understanding of actual copyright law, how it works, how its used, etc, is so exhausting and ignorant.
