It's not just about money, he’s probably too lazy to network or build relationships with these chicks. So he just goes along with whoever the agencies send his way; and for these broads, shooting with him is nothing more than checking a box and cashing the check. There aren't any porn sluts who do it for the love of the game anymore (with perhaps three or four exceptions if we're generous).
On the other hand, the money is no longer in mainstream porn; hoes nowadays prefer to take the Onlyfans route—if they market themselves well on social media—or they just earn more working as escorts.