Or the app shows you a few fake deliveries... If this story is real then there's no reason you can believe what the app shows you.
Not saying that it's not deceptive in some way, but it's more than just a surface-level difference.
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.
In my experience on Uber Eats, Priority definitely works.