But it has a pretty bad record of targeting "upward" and those few 'upward' targets suffer much less than the many 'downward' targets. "Ineffective in the best case" is not a very compelling argument.
If your argument is that powerful people land on their feet even when they face accountability, then yes that's true. But at least they're facing accountability and the value of powerful people actually having to face consequences when they do bad things can't be understated. It changes the culture of power.