I think you are getting confused about the definition of cancel culture.
Definition one: Not supporting celebrities when their problematic actions come to light. This is the one that was made to prevent people from banding against or facing consequences for their actions.
Definition two: A harassment campaign where people bring up actions from years ago even when they changed, taking things wildly out of context, and calling out in bad faith to bully small-scale content creators.
The commentor is talking about definition one here, and it seems that you are talking about definition two.