Amazon does not have an exceedingly high profit margin, and my understanding is that a lot of it comes from stuff like AWS, not Amazon deliveries - correct me if I'm wrong here. So I'm not sure that "three amazon deliveries a day" - if this is even common - is why that man is personally rich. Even if it were a big source of revenue, that would go into Amazon's coffers, not necessarily his directly.
Another way to look at this: Even if Amazon is wildly successful, does that mean Jeff Bezos specifically should become filthy rich as a result, instead of all its employees and investors? How should the gains from successful entrepreneurship be distributed?