I could see how the restaurant delivery would be worse if that particular restaurant is bad at delivering. Also, the app model does seem like it should be cheaper at scale by using the deliverer’s labor more efficiently.
This is a weird set of complaints.
1. Usually, there would be some lag time between when you order the food, and when the restaurant finishes making it. This would overlap with the time required for the driver to go to the restaurant and pick up the food; the app model isn't actually introducing a delay there.
2. Restaurants that do delivery themselves also use the same driver to deliver multiple orders at once. You're definitely better off with a dedicated driver, but the restaurant is much worse off. Again, this would not appear to be related to the app model. We order pizza and pick it up ourselves, because if the pizza place delivers it, it arrives stale and we pay extra for delivery.
That's not how it works. I order a lot and the driver is always there to pick it up as soon as it's ready. The driver obviously gets notified about the delivery as soon as the restaurant confirms the order.
One Friday night here in Sydney, it was raining like crazy - so we ordered in some food from one of the online groups. 2 hours later and multiple talks with support and they were still telling us stories about how it's nearly there.
We eventually called the restaurant directly and the food had been sitting ready for 90 minutes on the counter. The service just had all their gig-economy-staff decide this isn't the gig for them in bad weather, so no one was available to pick it up and deliver it. They said we could pick it up ourselves but we didn't really feel like old food at that point so we cancelled and drove out somewhere else. Being lied to was the most annoying part.