You can't be against cancel culture but for all the tools that allow its implementation.
In most civilized countries including the US you couldn't put up a sign that said straight white males only. In the US you cannot discriminate based on protected classes including not not limited to Race, Religious belief, National origin, Age, Sex.
Ability to recognize and ban people at scale is absolutely a game changer whether you want to acknowledge it or not. It is not remotely "the same thing" because it allows previously impossible consequences and failure modes. You are thinking too small if you are considering only this silly show. This kind of feature is in many cases in theory commendable and logical but equally problematic.
Consider shoplifters an odious bunch if there ever was one. Were I a shopkeeper I would certainly want to keep a fellow that ran out with some goods from coming back and its only friendly to share such a naughty list with my fellows. Steal from one and find yourself unwanted all over town. What could go wrong?
What if I DID pay for the goods but I was incorrectly flagged? For instance came back in with my just paid for goods to get something I forgot and went out a different exit.
What if said flagged person now cannot reasonably obtain food or other critical resources? For instance more than a few private enterprise operate public transit resources and a huge portion of the US has exactly one ISP. For instance I work for one ISP and utilize another. If they banned people who work for the competition I would literally have to move.
What if the person did wrong 10 years ago and has turned their life around since? Computers never forget and communicate across jurisdictions.
What if flagging is used not to punish actual criminals but merely those we disagree with politically?
What if its used to punish those who write negative reviews or do too many returns. Statistically if our supply chain has a certain amount of broken trash and we serve millions of people a certain number are going to get a much higher than average number of broken things or have more than average bad experiences.
I for one have seen both return fraud and plenty of people who cause their own problems and then complain endlessly. Were I to operate a business I would kill for a way to eliminate such worthless customers. What about the collateral damage of those legitimately wronged?
Looking at your profile you complain about "cancel culture" but seem oblivious to the fact that cancellation is implemented either directly as a million decisions about one's own personal property OR preemptively based on vendors who are acting to protect themselves from those same decisions. What you are arguing for is the method for cancel culture to explode in the public sphere.
Do you really want to worry about writing an honest negative review, being mistaken for someone else, saying something controversial on the internet, revealing yourself as part of a group disliked by some, or subject to a database error and find yourself banned all over town? Do you want to talk to a drone who tells you the computer told him you can't come in and he can't fix it but you can talk to his equally useless manager who will tell you the same thing?
Here's a laugh for you. Lets suppose I took your comment wrong and decided your bit about straight white males was an indication of homophobia. I make no such implication herein but suppose I did and added you to a bigot list that was ultimately picked up not by a single bad list but a web of bad lists as maintained by multiple people who pick up and push their lists to other more pervasive lists like adblock lists.
You find shortly that you can neither buy a loaf of bread nor get a sandwich down the street from your house anymore because we have collectively decided that our "cool private property" is not for you. You find a way to get off one list 3 steps removed from the genesis of your discontent but are re-added later courtesy of a different list. Nobody will tell you why you are on their list nor even if you are they just tell you that you aren't welcome. You spend the next 5 years chasing ghosts never figuring out that a single post on hacker news is why you can't get that job you wanted.
Again you can't be against cancel culture but for all the tools that allow its implementation.