To be fair, it’s wild that anyone still employs full time delivery drivers. Every pizza place I’ve worked at either had an employee doing double duty, or used a third party that got paid per delivery. Paying someone an hourly wage to do a job that isn’t even guaranteed to be required (depending on the night) is some franchise-only shit, and I’m not surprised to hear even they’re moving away from it.
I used to be a full time pizza delivery driver. We had other duties besides just delivering pizzas. Things that we'd do in between deliveries and at the end of the night after everyone else was sent home besides me and the manager. I guess I'd fit in to your example of an "employee doing double duty". We also got paid a lower wage than everyone else since we were expected to earn tips.
We once got a new driver from another store in the same franchise. I was blown away when I learned at his old store they would literally just stand around doing nothing or read the newspaper in their car, waiting for deliveries to take (getting paid the whole time). That's the kind of store that would save a lot of money by switching to Uber.