A delivery person working for the restaurant works for the restaurant, and has reasons to care about both the restaurant and the customer - and in return, both have a reason to care about the delivery person. DoorDash, Uber Eats and friends are VC-funded multinationals that ruthlessly exploit restaurants and the delivery people, strip-mining the local markets, often ruining restaurants in the process. The mischief and borderline fraudulent behavior of those companies is well-documented, and regularly discussed on HN.