Sadly these days few retail stores are infected with smiles. Chains and big boxes are doing everything they can do to depersonalize and transactionalize customers. Amazon is at the vanguard with its self-service stores.
Often the cashier scanning stuff at the big box or chain just wants to get to the end of their shift.
My sister has this habit of not handing a cashier money until she is looked at and acknowledged.
Sometimes it takes a while.
A massive competitive advantage can be to run in the opposite direction and recognize people as actual humans. A smile at the checkout, where most customer interaction happens can make an outsized difference.
This starts at the top and can infect an entire organization. That couple of seconds it takes to pause, look at a person and smile is gold in today’s world.