In my area, Las Vegas, NV, Grubhub (and now Eat24) have a base rate of 15%. That is for use of the online ordering platform. Which does not include sending a driver for delivery. If Grubhub sends a driver, add an additional 12.5%, for a total of 27.5% of the value of the food being delivered. There can be some negotiation, take an online promo we'll waive credit card fees and the like, or 60 day 20% first time new customer rates, but for the most part, here in Vegas, Grubhub is 27.5%, if they send a driver. Eat24 doesn't have drivers, but GrubHub is integrating. In the case of GrubHub, the restauarant has the option of using in-house drivers, or dispathing GrubHub driver. There is no choice with the likes of UberEats, Postmates, and some others. Those services will dispatch a driver for all of their orders.
Again, here in Vegas, UberEats charges 30%, PostMates 30%, and Amazon 28%. And of course there are other services here too... DoorDash, BiteSquad, Slice, as example.
Most pizza venues have their own drivers on staff... they may have limited delivery radius which is why some of them sign up with the online orrdering/delivery services. At 30% the sale might not be a money maker, but you gained a customer. And you can buy larger quantities of food cutting costs for all orders. And really, you did not pay anything for customer acquisition... slap up your menu and details on one of the big services and agree to pay, but only when used. If no orders, there are no fees.