I'm not completely convinced. The argument is due to economies of batching delivery. But restaurants can batch their own deliveries too. That line is the "inven

I'm not completely convinced. The argument is due to economies of batching delivery. But restaurants can batch their own deliveries too. That line is the "inventory / order interface" and there's no universal optimal point for it, it will vary according to circumstances. Anyone who sells expensive food may choose to optimise for service, which means delivering themselves. Those who optimise for volume will eventually cut out the expensive middleman. Adding to which, the most profitable markets are the dense cities where there are already strong incumbents, which goes to pouring in capital as a substitute for building a business organically.