Iran already has a lot of issues. If the regime does collapse over night ala Soviets/Arab Spring by just making some mistake while reacting to all this pressure, I dont look forward to the amount of gloating Trump and Netanyahu are going to do.
The regime has been decapitated and it lives on. They planned for this for decades and built a resistant decentralized command structure.
Their army survived the first shock and is now engaged in a decentralized gorilla conflict (as they always planned) and everyone knows how that ends. (When US gives up without accomplishing anything and goes away)
The modern autocracies barely even pay lip service to such ideas