Egypt did not have one pantheon. It had several, each attached to a city, and it never felt obliged to reconcile them. Heliopolis derived the world from Atum and organised nine gods around him; Memphis had Ptah think and speak it into being; Hermopolis began with eight primordial powers in the dark water; Thebes made Amun the hidden source of all of it. These accounts contradict each other and were copied side by side for millennia.
What follows is a pantheon whose headship moves. Ra is supreme, then Amun rises with Thebes and is fused into Amun-Ra, then Aten is briefly imposed and then erased. Which god is greatest in Egypt is substantially a question about which city is greatest, and the theology tracks the politics without embarrassment.
Succession in the myth is not overthrow but retirement. Ra grows old, humanity rebels, and after the reprisal he withdraws to the sky on the back of the celestial cow, leaving the world to be governed by others. The struggle that matters afterwards is not a son displacing a father but Horus and Set contending for an office that a tribunal must adjudicate, over decades, with legal argument.
The king is the hinge between the human and the divine. He is Horus while alive and becomes Osiris at death, and by the New Kingdom the ordinary dead were making the same claim for themselves. A very few commoners, Imhotep foremost, were raised to godhood centuries after they died.