I do appreciate age compliance shops even though neither I nor any family members do/have done them due to age. I recognize that the corporation is doing the shops because it is a lot cheaper to hire a shopper than to pay the fines for an employee caught breaking the law. But the laws are there because society mostly feels that alcohol, cigarettes and movies or games with excessive violence or sex need to be limited to those with the maturity to handle them responsibly. Age is an arbitrary indicator of maturity but probably the best we've got that is quick and clean.
There are, of course, other types of compliance shops, and indeed every shop we do is about compliance. If an employee is trained that they are to greet incoming customers and they don't, they are not in compliance. If they are trained to explain the return policy and they don't, they are not in compliance. If they are not to have more than 3 visible piercings and they have 8, they are not in compliance. If the public restroom is to be monitored to keep it well supplied and there are no paper towels or tissue, they are not in compliance. etc.
If we were not checking for compliance we would not be doing shops at all.