For thousands of years, human workers and artists have trained themselves by looking at copies of other people's work, and used the ideas and inspiration the gain from that material to produce new works. Artists will literally sit down and copy another artist's work as part of training. This happens as a matter of course. Sometimes the new works produced after training are fresh and original. And just as often, they are derivative copycats (see: fan fiction, most clothing, most music, half the stuff on DeviantArt, etc.).
The law is only concerned with a creator's output, not the input.
If you produce and distribute something that's an obvious copy of someone else's work, that could be a copyright violation. However, if what you produce is sufficiently original, it's fair game, regardless of who you were inspired or trained by. The law does not require compensating or crediting those who inspired you or helped with training. Again, the law is only concerned with output, not with training, not with inspiration, not with input.
What you are advocating for is a huge change. Would this change apply to humans who are learning/training by looking at and copying others' work? If so, that would be a nightmare. If not, why not? Why only apply it to AI? Because the AI is more efficient at it than humans?
If that's your reason, could you justify it? New technology is always more efficient than the status quo. That's the entire point of new technology. Making laws to stop it accomplishes nothing except limiting technology in order to protect old jobs and business models. Why should we do that?