I think people in the US are seriously discounting this. The only thing that Iranian forces have to do is keep lobbing drones. You don't need leadership, heavy industry, or even a lot of drones as long as you keep lobbing them.
It takes very little for them to keep disrupting things which affect the global economy.
Even if leadership changes at the top and isn't killed, why would independent cells of fighters stop?
I think there's a huge possibility that Iran can keep being disruptive longer than the US is willing to spend $$$$$ bombing and intercepting.
One nuance here is where that $$$$ actually goes. The US has a history of diverting a staggering amount of money to the war companies every 2 decades or so. The spend here might be the goal, not the cost.