You do realize that they are actually tracking the device itself by the hardware MAC address and other device fingerprints.
The email is just a bonus to let them legally spam you. Anti-spam laws have an exemption. If there’s a prior business relationship like shopping in their stores, they can put you on their spam list unless you opt out.
Bogus email only helps for spam but doesn’t do anything about tracking.
EDIT: For Android when there’s a Captive Portal like the screen shot. devices will use Persistent randomization which while not the hardware MAC will remain the same for the same network where they can track your visits.
GrapheneOS let’s me do a per-connection randomized MAC.
I’m sure they do collect a lot more about my device, but there’s not much I can do about it short of wrapping my phone in tin foil.
Don’t forget to disable wifi and bluetooth before approaching the store, as those give off unique identifiers too.
