Cancel culture is terrible because the goal is to destroy people who hold unpopular beliefs. It not enough to refute the belief. The transgressor must be punished with the full fury that internet-enhanced social pressure can bring to bear. The goal is to punish and destroy.
Shaming and social opprobrium can work in a community where there's interaction between the parties. This also allows for grace and restoration. It doesn't work in the global twitter-verse.
Civilization is the ability to live in peace with people that aren't like you - you may disagree with them, disapprove of them, or dislike them, but you don't seek to destroy them. We seem to be losing it.