I think the big problem DoorDash and the like have, is they obfuscate the capacity connection between real restaurants.
In the real world, if you drive up to a McDonalds, and there's a line around the building for drive-thru, you can make a decision. (Is it worth the long wait, or not?). In the real world, if you go to a sit-down restaurant, and they're full, they simply turn you away (often with a buzzer or a text callback or whatever, for the 'next available table') and you can make a decision. (is it worth the long wait, or not?).
DoorDash and the like, knows about (but intentionally hides) whether a restaurant can actually handle your incoming order -- they never admit if a restaurant is busy or falling behind, because then a human might use that information to decide not purchase.
So, DoorDash implies to humans that restaurants are open and ready, orders stack up indefinitely far beyond what a real-world restaurant normally would take, and real-world restaurants have to magically 1.5x to 3x their capacity out of thin air.
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It's not a systems-based issue -- no combination of "moving orders" or "separating orders" or "more apps / AI" could solve it. It's a fundamental capacity issue -- restaurants (especially drive-thru places) don't staff enough people to handle making more than a certain number of orders at a time, and shuffling that capacity from window to counter to drive-thru is just obfuscating that fact.
I observed the same thing around the time online ordering became more popular. It used to be that at a lunch spot, cashiers or phone operators could restrict the order flow a bit to keep the kitchen from getting overwhelmed with orders. DoorDash et al. have no interest in that, they only want to take as many orders as possible, as quickly as possible; they have an incentive to obfuscate the real wait time from customers.
Waiting in line to order your lunch is skin in the game. Even the sight of a long line is enough to help load balance lunch orders between restaurants. I do wonder though that if restaurants could feed back to DoorDash and limit the order flow with online-only "surge pricing", if that would help in the same way to forestall kitchen overwhelm.
There is a Starbucks in downtown Chicago that is always empty, but has a 30 minute wait due to online orders.
It is incredibly frustrating cause you have to wait while they fulfill online orders.
They should have priority queues to ensure that certain order types take priority