First mover network effects. Also, not knowing the market. It’s hard for a company without at least a cursory local presence to get local restaurants to sign up for things. There is a significant burden on the restaurant to get onboarded for a delivery company, so there has to be a good reason to do so.

But, there is definitely a margin to be had here… if you could have a lower cost delivery service that managed the white label backend like DoorDash, I’m sure you’d see companies flock to it for their in-app delivery. (Think McDonalds delivery ordered in the McD app)