Consider that the AI companies didn't ignore copyright. They didn't copy anyone's work. They didn't breach any of the licence terms in existence at the time. Are you sure you're not just sour grapes because it's too late now?
In respect to the subject of compensation, if somehow there was an agreement for compensation, then the claimants would need to show their work specifically was copied. Inspired works do not require consent of payment to existing copyright holders. Then they would need to be able to show what proportion of their work was copied against any other parties vs new creative elements in the work in question.
Recently Ed Sheeran won a
“The four-chord progression at issue—ubiquitous in pop music—even coupled with a syncopated harmonic rhythm, is too well-explored to meet the originality threshold that copyright law demands,” a panel of appeals court judges wrote. “Overprotecting such basic elements would threaten to stifle creativity and undermine the purpose of copyright law.”
It would seem from that ruling that even people can be inspired and creative directive works without royalties.