[diggernet]

Based on my own experience, I would slightly adjust what you say. The wealthy neighborhoods did have more repeat non-tippers than they should, but they also had some of the best tippers. There were also a fair number of non-tippers in the crappiest poor neighborhoods, but I was fine with that.

On the other hand, the "gig economy" has really screwed up pizza delivery since the shops started laying off their own drivers. There is no control over quality, and tips don't really count for anything anymore. The dude who showed up an hour late with a cold pizza got no tip, but so what? He'll never be back, and doesn't answer to the manager of the restaurant. Good tip for a good, prompt delivery, sure. But that won't earn better service, because we'll never see that driver again, either.