Oh, restaurants totally change prices based on eating in or delivery. Often, places will have different prices in different apps too — depending on what the costs are for them. I’ve literally played arbitrage between Seamless, DoorDash, Postmates, and a restaurant’s own website before to find the lowest price because the price was different everywhere. There are also places that won’t list in an app but will have delivery on their own website that is then sourced to DoorDash.
"I’ve literally played arbitrage between Seamless, DoorDash, Postmates, and a restaurant’s own website"
If you bought food on the cheaper platform, and tried to make a profit by selling it for more on another platform, then you would have 'literally played arbitrage'.
It's the same as when you buy an item from an online retailer, that is shipped directly from the manufacturer (e.g. a large ClosetMaid kit). The price at Amazon and Home Depot might be different, even though the same company is supplying and delivering the item to your home.