Regime change has to come from the people, like Syria, if not from the people, it can only be achieved through total defeat and years long occupation, like Japan/Germany after WW2. Obviously, we don't want to do the latter. All these bombing runs do as they've always ever done is unite Iranians under the flag of Iran, not necessarily under Khamenei because a lot of Iranians despise him, but united as a country for a common cause, it breeds nationalism and extremism, innocents die and their anger is then directed towards those doing the bombing (America/Israel).
And even IF Khamenei was overthrown, it would now more likely be due to Iranian hardcore nationalists believing he isn't being tough enough against Israel, it's very delicate to actually get the right person in charge after a regime falls and often it just ends up with another breed of terrorist taking over, so ultimately, if America and Israel's goal was to cause regime change in Iran for someone better to take over who is more sympathetic to America/Israel, this would probably be the worse way they could have gone about it.
