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.
Does it? Consider the numerous celebrities, comedians, and even The New York Times.
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.
Honestly you're making generic arguments in favor of mob rule. I get the appeal, but it's reprehensible and I can think of precious few things as boring as debating its merits. Let's just say we agree that cancellation is as good as mob rule and part ways.
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.