retail workers arent putting miles on their car and buying gas to deliver to you. they're ringing you up at a cash register
if you don't wanna tip a delivery driver, you should pick it up yourself if you dont wanna tip a waitress, just order it to go
Retail workers don't just ring you up on the register. They assist you with a number of things when you are in the store, that's all a part of customer service.
Retail companies also employ people to deliver items to customer homes. Hell, Amazon contracts people to deliver things to people's homes, but where is the expectation of tipping there?