Iran just needed to survive. There is no expectation for it to win against the nuclear super powers. It's a wonder it survived even for this long.
Bombing Iran into surrendering was never a realistic outcome.
There was regime change, just not in the direction anyone else wanted.
Except it may be even worse than that. While you might expect some infighting among SA factions, the Revolutionary Guard is a distributed force that's ideologically united by both a common religion and a common cause.