If I order an entree at a restaurant, I want that meal to be my biggest meal of the day, with rare exception. A meal at a restaurant is a special occasion, and should be a source of hospitality. The prime way for the restaurant to provide this hospitality is to accomodate my hunger! If I am still hungry at all after ordering and finishing an entree, then I am not satisfied.
I'm totally fine with eating a bunch of cheap filler sides (fries, rice, etc) to make me full. Often times, I feel like more expensive restaurants do a worse job at actually filling you up with the entree, because they want to tack on appetizers, small plates, etc. I leave these sorts of restaurants angry sometimes. Just give me food, dang it!
To reply to your thoughts, I always had read that restaurants and food in general were cheaper in the U.S. Curious that you found the opposite to be true.