well they are also vulnerable like we are, they cant get happier with making more millions then they already have, the step between super rich and mega rich doesnt add to more happyness imo, when we buy something expensive like a car it adds to our happyness because we are thrilled about it and may have red a great deal about the car on forehand, but if you can buy 40 of them and you are already rich would it add more in happyness? its all relative.
they also die, friends and family of them die, get trapped into scandals, cant go outside without these sewer tabloid rats laying in the bushes, and in fact cant buy health.