The reason he's still in that marriage is because of ego. Ironically he's taking more Ls continuing to stay with this woman instead of just calling it quits and staying single for a minute before taking another shot at a new relationship with a non famous woman. He wanted a normal marriage and *this* is what he ended up in. She didn't want to be married, she told him in so many different ways but he just can't accept it so she'll continue to humiliate him and take his career down with hers.
Don't be shocked if he suddenly starts getting offers when he announces a divorce. His kids are grown, they both know they don't like each other and are likely already just treating them as divorced parents. It's time to dissolve the contract.