> Why have a full-blown car or motorcycle when you can have a tin can on wheels deliver stuff?

For one reason, to prevent people from stealing the goods. I used to deliver pizza. It was pretty much a given in certain areas that if I was not very careful about locking my car that I'd get pizzas stolen out of it while I was parked making a delivery.

A self-driving igloo cooler is just going to get kicked over and emptied.