I absolutely think that exceptional service is possible - for example, when I visit a restaurant with my elderly grandparents who have some extremely particular dietary restrictions, and the wait staff patiently discuss our options, help them create a meal that satisfies their preferences and remains interesting, I find that exceptional. I've had wait staff give us genuine recommendations on the menu, with honesty, indicating the dishes they don't like (much more rare) as well as those they do resulting in a good meal - I enjoy that candor and am happy to tip for the recommendation. I've also had staff stay late and keep a restaurant open because we were on the last train into a station with nowhere else to go and eat and didn't speak the local language - I found that exceptional as well.