What happened to Sacco is for me under the heading of "This process is not pristine. It is not without issues, occasional oversteps, and other problems that arise when human beings are involved." And, what she said was also completely inappropriate and overtly racist, and although she did lose her job, she didn’t go long without one and is currently doing just fine on that account. “According to her LinkedIn profile, she left FanDuel in 2018 and went on to become the VP of communications for Match Group and has been their chief communications officer since February of 2020.” Overwhelmingly, the people who get "cancelled" absolutely deserve it and also don't suffer any real lasting consequences. Guys like Jordan Peterson who cry about being cancelled and having their voice censured are usually still making 6 figures a month flapping their gums.

The real point is that cancel culture would not need to exist if actual listening, actual dialogue, and actual change were taking place. As King noted in a speech where he was asked to condemn rioting:

“But it is not enough for me to stand before you tonight and condemn riots. It would be morally irresponsible for me to do that without, at the same time, condemning the contingent, intolerable conditions that exist in our society. These conditions are the things that cause individuals to feel that they have no other alternative than to engage in violent rebellions to get attention. And I must say tonight that a riot is the language of the unheard."

Cancel culture is rough justice because for the most part, no other type of justice exists. It is the language of the unheard. In addition, I don't see any real chance of socialism truly impacting longstanding racism, misogyny, or other types of dominance hierarchy stratification even if it were to be accepted on an economic level (not likely either, as you pointed out).