> Under that model, wouldn't drivers only want to work for the busiest restaurants?

It doesn't take many orders to keep an individual driver busy. Typically the restaurants would manage how many, and which, drivers worked each night. If the night was unexpectedly quiet then a driver might finish early.

> With delivery apps, a restaurant can have just a few orders per night and still be open for delivery.

Yeah, the main benefit of delivery apps is enabling restaurants who primarily serve sit-in diners to deliver also. The overall benefit to delivery focused restaurants is much more tenuous.

> I would bet that there's an order of magnitude more deliveries happening (and drivers working) these days vs pre-Uber.

Perhaps, but if a driver was already busy all night under the previous model, then they're potentially harmed by the current model.

Honestly I think there's a great role something like Uber could fill, simply as a nationalized, not-for-profit tax funded arrangement that businesses could opt into, maybe even a branch of the post office. Ensure delivery people get good benefits and pay for doing a needed job, and the service brings those people, restaurants and stores, and consumers together. We could make things more convenient for people, provide businesses with more opportunities to sell their products, while providing a lot of jobs to people who need them, and also cutting down on the number of vehicles going around at any given moment.

The main drawbacks to these services are the outrageous fees they charge to make money, and that there's more than one so drivers and businesses have to manage an array of phones or tablets. This would address both of those things.