For example, from Uber's terms for UberEats restaurants[1]:
"Notwithstanding anything to the contrary in this Section 5, Merchant may not make any Item available to Customers through the Eats App at a price that is higher than the price that Merchant charges in-store for similar Items. Merchant agrees that you will not make an Item available under this Agreement at a price higher than the amount Merchant is charging for similar Items through any comparable platform for food delivery services."
[1] https://www.uber.com/legal/en/document/?country=united-state...