There are legitimate times when a person is "cancelled" unjustly and it's a case of the public opinion being turned against them before all the facts come out.
However, most of the time, any claims about someone being "cancelled" is just someone being held accountable for their actions, actions that they SHOULD be held accountable for.
Take Mike Millbury for example. After his firing, there were SO many complaints about "cancel culture." But that wasn't the case with Millbury. That was a case of a man with very sexist tendencies toeing/crossing the line one too many times and the network finally deciding he probably shouldn't be allowed to represent them on national TV. The "final straw" wasn't the worst thing he's said, but the cumulation of history made it a wide idea not to continue to give him a platform.
In more recent news, Dr. Seuss isn't being "cancelled" either, despite the claims otherwise. His own estate is removing certain books from production because they contain blatantly obvious racist images and language. And everyone's aware that it's likely a product of the time in which he wrote those books rather than a strike against Dr. Seuss himself, but it's still not something we should be showing children in their books.