Copyright as a concept is prescriptive not descriptive. It doesn't appear from an observation of the laws of reality, it's law to produce certain outcomes, so what copyright applies to is a question of what will the legislative bodies decide to do.

It's entirely valid to consider the act of training via ML a right granted by the creator like reproduction or performing, simply on the basis of protecting human art. The comparison with human learning can be made irrelevant (and IMO it's not the same fundamentally).

This is currently a discussion about plagiarism (the ethics) and what the outcomes are from unrestricted GenAI. How copyright applies to GenAI is a question for later, informed by the discussion by society at large (and lobbyists).