Why does anyone need to opt out at all?
You don’t need to opt out of being punched in the face when going out in public, why do you need to opt out of unwanted, unmandated tracking when going shopping for essential items?
Mostly to make life a bit more annoying for the stores that try to implement this sort of thing- raising the cost to implement it.
This!
Getting punched in the face vs. walking into a private store that has a type of surveillance you disagree with are entirely different things...