Costco has had someone check your purchases for years when you leave the store.
And in a lot of cases they are pushing the customers in that direction.
Limited in store stock.
Lock everything up and not have enough employees with keys.
There are lots of advantages to fewer or limited size stores. No rents, they need less employees. More centralized inventory.
The attempt to reduce the number of clerks with self checkout has not been the win the stores had hoped. Higher shrinkage do to unintended customer mistakes and intentional shrinkage by the outright thieves.