Joseph had been granted absolute power to rule over Egypt. Pharaoh continued to reign over Egypt, so Joseph started to do Pharaoh’s bidding.
But, as we see, power corrupts, and absolute power corrupts absolutely.
Through taxes on grain produced during the good years, Joseph had amassed all the grain supply for the government. He is now selling it back at a far higher price than he bought the excess harvests over and above the taxed harvests during the good years.
These are the steps to gain total control over the people.
5. Reduce people to servitude and slavery in exchange for some of the food.