(1) In a fully automatized economy, owning a link in the last mile of food delivery is valuable.
(2) You could make a USP out of "our robots are clean: best hyghienic condotions for your pizza." This works until some journalist finds leaked machine oil in your tomato cake.
(3) The wisdom of the ages speaks of being ten times better. The design goal for the iPhone was to be ten times better, than other smart phones of that era. Not just better. Ten times better. I fail to see how current pizza delivery can be improved ten times. Maybe it can. But it's pretty good already.