That's what I was thinking. 5% is the upper limit of the fraction of his wealth that a rich person could safely spend each year anyway. So his income is no different than if he'd kept the money. The only thing he has lost is the ability to change his mind about where the principal goes when he dies.
That kind of salary still lets him build substantial personal wealth, so if he manages it wisely there will likely still be quite a large sum to pass to his heirs.
