That sounds great, now convince consumers they don't want Monopoly one-stop platforms where they can order/purchase anything they can think of.
The restaurant then can broadcast the driver demand and delivery prize in their website. Drivers can be scanning all the restaurants in their area and decide if they want to take it or not. Restaurants over time will build lists of reliable drivers whom they will favor when matching.
I'm not saying a system couldn't be designed/work. I'm saying time and time and time again, it's been shown that consumers want a monopoly platform for convenience.