How are you certain that the food you are getting is from the establishment you ordered it from? Why can't I run a shadow kitchen pose as your restaurant and steal your business?
Does the fraud begin when you serve different food, or does it begin when you represent yourself as the restaurant without their consent? Everyone would agree passing off different food is fraud. Using a different number and marketing yourself as jdmichael's friendly delivery service is not fraud, since the customer knows they are not working directly with the restaurant. Using a different number and marketing yourself as the restaurant IMO is fraudulent.
I think everyone is in agreement regarding the information misdirection stuff being unethical at best and certainly potentially fraudulent. But simply listing restaurants and offering to deliver food from them is not that.