I worked at a pizza place with a drive through. We sold many items that were non-pizza like wings, subs, salads, burgers, desserts and side items like fries, mozz, etc. My girlfriend's family owned the place, so I was familiar with more than just grunt work and had some inside insight into the business numbers that normal workers do not get.

We would never have fulfilled an 18,000 water cup request.

If someone came by with a catering sized order in the drive through, we would have had them park somewhere and told them a relative estimate of how long it would be. Sure, maybe someone would have started on a couple of things, but we wouldn't be able to fulfill such large orders in the time it took between placing an order and the window. There's only so many workers.

There was obviously plenty of food waste, but that's baked into the cost of the items.