Seems to me a manager or above has to certify that a necessary skill is not available from a US worker before AND while an H1B worker is in place. As I recall, they have to certify and sign a form saying the needed skill isn’t available, but they don’t have to identify the steps they took to find a US worker. That leads to a lot of misuse.
I’d like to see an audit of the thousands of Walmart H1B positions from the last 10 years done to see just how many were valid and how many were fraudulent.