It depends on the mode of service, which in turn depends on how fancy the restaurant is trying to be.
At home you would not change cutlery or bring out a plethora of dishes each time you switch from one food item to another. You have a fork, maybe some chopsticks or a knife, in rare cases a grapefruit spoon, crab claw, corn cob holds, whatever?
Why would you expect more from a restaurant? Because you are paying them good money to create a special experience for you, that's why. Starting a new meal course with old dishes and utensils could muddy the flavors, but more importantly it cheapens the whole experience. With each new dish It's like facing a beautiful, limitless new day in last night's underpants. Personally, being a drought-conscious Californian,I think, better to face a new day with an old fork than waste four ounces of water and twenty-two seconds of staff time replacing the fork. But that's my dining experience, most people would rather attack their twenty five dollar chicken with a new fork.