Note: the Verge article links to this blog post, describing the situation in more detail: https://www.readmargins.com/p/doordash-and-pizza-arbitrage
They could have made another $5 per 10 pizzas after order #1 by just delivering the pizza to themselves and sending the same boxes back out in the next delivery, and so on.
Thank you, this was a fun rabbit hole to dive down. That blog also has a well-argued article about Zero Interest Rate Policy which relates to the doordash story: https://www.readmargins.com/p/zirp-explains-the-world