The food is often secondary. Sometimes I want to sit in nice surroundings with interesting people and know that someone else is going to think about presenting me with good food I might not have thought to try myself, and a staff exhibiting a high degree of professionalism will bring it to me. Often, that place is in a location with high rent (for the restaurant, and the staffs' landlords), so it's not cheap.

Sometimes I want pizza and beer, and that can be 100% as good, too. Usually cheaper if only because it's more efficient, though.