He was a nothing. "The President of Iran" is meaningless. So is their "Parliament", and everyone in it. So is their "Judicial System", and all the judges and lawyers in it. None of them have any power or are in actual control of anything. It's a vapid illusion. They're just there carry out the will of the Supreme Leader and to fool morons into believing that it is any kind of "Republic", Islamic or otherwise, and has any kind of popular support.
Iran is an absolute Monarchy, like all leftist systems. It is much more absolute than when the Pahlavi's ruled. All power rests with the Supreme Leader and his "Guardian Council" constitutionally. The council is basically half Imam's "expert in Islamic Law", and half just a collection of the cronies of the Supreme Leader.
Eliminating all of the actors pretending to be in service to this "Islamic Republic" would change ZERO. You have to kill the king, and everyone who has the faintest idea understands that.