While I do think it's technically possible and the right thing to do to determine what original works were used in derivative art to pay royalties, the reality of the situation is that those payments would be a small fraction of what they make now since the whole point of generative art is to be able to reproduce derivative works for a fraction of the cost. Unless the demand for art increases proportionately with the decreased cost, which it can't, compensation with decrease, and as more art goes into the public domain the compensation will decrease further.
This will not save artists and they need a back up plan. I think the future of art will probably be that artists will become more like art directors or designers who are responsible for having good taste, not producing the original work, but even that will have greatly diminishing demand as generative AI will handle most basic needs.