Stalin raved and cringed on his deathbed. Pharaoh perished with his host in the Red Sea. Ultimately, Passover is about sovereignty. He did so to fulfill His design. The crucible of Egypt was necessary to burn off the spiritual dross of idolatry.
Slavery is but the most visible form of servitude.
It's leaven that gives bread and cake its taste and appeals to our senses. Bread baked with yeast is compared to the ego, which also becomes inflated. Thus chametz has come to symbolize all of the things that enslave us with their cunning allurements. They control our existence as surely as the edicts of any tyrant. Their incessant demands sting us like the taskmaster's lash.