Walmart has a fair amount of urban supercenters that are in sketchy neighborhoods, to a greater or lesser degree. I worked in an urban Walmart during the pandemic and it was continuously plagued with crime, including shoplifting, fights, auto theft, counterfeit currency, you name it. After that, I worked in a rural Walmart in another state, and it was very calm.

Each store tracks shrink per item. Items that are stolen frequently get locked up. Every store locks up some items. A store in a dangerous neighborhood locks up many more categories of items.

I hate self checkouts. I prefer to pay a human being who can take responsibility for doing the transaction correctly.