I mean why would Rock be bitter? Deep down he knows he's lapped Triple H in every facet of life, and he knows Trips knows this as well
Imagine the ether you would feel if a guy you looked down on and bullied at the start of his career, surpasses you and ended up becoming one of, if not the greatest superstar in wrestling and an icon, then he moves onto Hollywood and becomes an A-List celeb there and is universally loved
And he still gives back using his celebrity status to the company you're running and will eventually inherit.
Deep down you hate this guy but you need him and he doesn't need you