When I choose priority delivery in Uber, I can see the driver go to the store, pick up my order and drive directly to my place. I also see the driver usually have 1-2 stops on the way if I don't select that. If there's enough gap between myself and the restaurant, priority is absolutely a time save.
It would have to do very accurate parallel construction of GPS signal to lie about the driver's location yet correctly predict the arrival time, which cannot be faked.
It shows the guy going to the restaurant, the same guy that eventually shows up at my door. It shows it on the way to a couple of deliveries and takes as long as extra deliveries should roughly take. It shows the immediate previous delivery when it's almost delivered, and the guy spends about as long as i'd expect at that place.
Not saying that it's not deceptive in some way, but it's more than just a surface-level difference.
But that makes sense. Why should the driver be aware of who is marked Priority? It might also open up the app company to liability (oh the app told me it's a "Priority", so I drove faster and crashed). The driver simply goes where the app tells them to go.
In my experience on Uber Eats, Priority definitely works.
If this is Uber then it's not legitimate.