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.
All it does is that it puts you first in queue (assuming two people don’t pay priority in the batch). So it’s a gamble on your end.