How do they not make copies? Do you know how a computer works? Ever heard of RAM? (At least the German Urheberrecht recognizes this clearly: You can't do any processing on any data with the help of a computer without at least making temporary local copies, so there are exceptions to some rules. I'm quite sure common law copyright also recognizes this!)

Also the claim that this is not a derivative work is actually one of the disputed claims here…

> Any other result means that all AI development based on training models is going to grind to a screeching halt, because essentially all training material—text, pictures, recordings—is copyrighted.

Exactly, it's all copyrighted! That's why you can't use it for whatever you like. That's the whole point of copyright.

As a result this means that whoever wants to exploit that work in said way needs to buy (or get otherwise) a license!

Nobody said that feeding AI with properly licensed work would be problematic. Only the original creators need to get their fair cut form the outcome of such process.