I will strongly suspect that the big centres in california will do likewise, or potentially the state as whole.
And it's no wonder. Restaurants delivering have very low overhead. A phone line and a delivery driver.
When you're on grubhub/doordash/etc, now somebody has to pay for a mountain of software engineers, marketing expenses, servers, customer service people, executive comp, etc. It inserted an expensive middleman where there was none.
alas, it's probably still a better option than each restaurant trying to build their own website/app. But not better than picking up food or calling the restaurant for delivery.
That model was vastly preferable, as delivery people were familiar with the neighborhood and you wouldn’t find yourself accidentally ordering from a restaurant on the other side of Manhattan that will essentially guarantee your food will be cold.
As far as the number of engineers required, I think you vastly underestimate the tech and infrastructure required. Sure a few dozen engineers could build the core matching and routing engine and the restaurant and delivery person apps, but all of the scaffolding around that is huge. Who does customer support? How does the customer get ahold of the delivery person? What happens when an order gets misdelivered? How do you deal with the various regulations in different municipalities around pay? Heck, paying people is a few dozen people alone.
And then you have to think about supporting all of these things in places where the delivery models might be totally different- car delivery is totally different than walking delivery. What about users whose orders are late? In some places they have health regulations that preclude delivering food that has been waiting for over a certain time. The list goes on and on.
I think in general it works for pizzas because pizzas have very high margins so that some or all delivery costs can be bundled in the retail price of the pizza.
Keeping wages artificially low (with Immigration for example) disincentivizes businesses from investing in new technology (aka LSDs => Labor Saving Devices). Productivity declines. The economy stagnates.