So any art done in a style of another artist is theft? Of course not. Learning from looking at others is what all of us do. It’s far more complicated than you’re making it sound.

IMO, If the derivative that the model makes is too close to someone else’s, the person distributing such work would be at fault. Not the model itself.

But again, it’s very nuanced. It’ll be interesting to see how it plays out in the courts.

The model is the thing of value that is damaged.

It does not get damaged, it stays as it is. Also it's a bunch of floats, not a computer.

But making works derivative from someone else’s copyrighted image is a violation of their rights.

"Derivative work" doesn't mean "inspired by". For a work to be derivative it needs to include major copyrightable elements of the original work(s). Things such as style aren't even copyrightable. Character design is, but then you should wonder whether you actually want to enforce that in non-commercial settings like fanart, even commissioned fanart, if e.g. Marvel doesn't care as long as you're not making movies or actual comics. They gain nothing from there not being, say, a Deadpool version of the Drake meme.