>>21664920depends on the situation, a coffee shop or takeout food it's not going to be a problem
if you sit down in a restaurant and eat a $200+ dinner and don't tip, they might follow you to your car and ask you what was wrong with their service in hopes you'll be shamed into adding a tip
but you are correct you're taking a chance if you pay before they package up the food for order-ahead places, anything can happen then
the last oil change place I went to asked for a tip
not going back there, needless to say