Everything is a trade-off.
I’m sure there is some shoplifting.
Walmart has high def cameras with artificial intelligence software deciding how “honest” each patron is.
That’s why you don’t see grandma at the store door anymore, it’s a robust youngster with an earpiece who gets the command to look in your cart on the way out.
I’ve seen it many times in the last several months, and it happened to me once, although I had scanned everything and passed muster.
I refuse to participate when they try to check my cart. The second I pay for it, my items become my personal property and they are then violating my Fourth Amendment rights. Their time to check me is before and during the transaction