I’ve gotten drivers from the local pizza place using grubhub but sometimes would get a grubhub driver so at least with grubhub they must have a choice. That pizza place used to have their own online ordering but they sold the business so now they use slice which seems to charge a flat fee. I don’t think slice has their own drivers.

I really only ever order pizza from local places, I’d expect normal restaurants to not have their own drivers.