The training data containing non licensed artwork is an extremely short term problem.

Within even a few years that problem will literally be moot.

Huge data sets are being made right now explicitly to get around this problem. And ai trained on other AI to the point that original sources no longer are impactful enough to matter.

At a point the training data becomes so generic and intermixed that it’s indistinguishable from humans trained on other humans. At which point you no longer have any legal issues since if you deem it still unallowed at that point you have to ban art schools and art teachers functionally. Since ai learns the same way we do.

The true proplem is just that the training data is too narrow and very clearly copies large chunks from existing artists instead of copying techniques and styles like a human does. Which also is solvable. :/