Wasn't there a family that would only have one heir to the money, incentivizing having only one or 2 children and both raised\groomed to not fuck up the money. Like if backup kid needed money, they'd get a loan from the trust but have to pay it back with interest. They have a family estate so if anyone fucks up they don't end up homeless. With so many advisers making sure the money is OK above all else.

I swear the Medici family still has an heir living off of that generational wealth