Backstory: I've used door dash a lot recently and like it but I'm very away I'm using door dash. I had one issue with an order and ended up resolving it faster by calling the restaurant directly.
The Idea: A white labeled delivery service for local restaurants.
Deep Dive: This service would be a premium offering for restaurants. Compared to door dash or other delivery services, you would have deeper connection with restaurants and would be able to readily handle most issues. You would provide each restaurant with an account manager who would visit the restaurant on a frequent basis and would be required to have knowledge of their menu items, allergy restrictions and food prep times.
To the end customer, this would function similarly to door dash but you service would appear to belong to the restaurant and the restaurant would own the customer and their data.
Validation: Delivery services are already offering a great value for restaurants but they own the customer.
Monetization: You would charge a delivery fee to either the customer or restaurant.