It sort of starts with what is "canceled" to you. Do you mean never work in the industry again? Lose all fans? Face legal repercussions? Someone like Louis CK had a reckoning during me too. It wasn't enough to face legal charges, but he stopped for a bit and lost some fans, but not all and came back after a couple years. For some that was enough, while others were pissed he still had a platform at all.
It also depends on the type of celebrity or artist. Some have very little barriers to entry to get their stuff out there. A YouTuber just needs to be able to post a video where bands or live performers can have venues cancel on them. Even if YouTube steps in, someone like Alex Jones can move to another site and keep making content for his fans.
I see canceling as a means of spreading awareness to others that a celebrity had done something wrong and isn't worth spending time or money on. It is often a stop gap when our legal systems don't have means to right a wrong. If a celebrity did something morally wrong but legally gray they shouldn't get off scot free