> What you’re doing is akin to tipping 5% in restaurants in the US and only tipping 15% when you have an outstanding experience. In reality, restaurants workers in the USA would expect 15% to 20% unless they dramatically fucked up.

This is actually the sole reason I don't go to restaurants/diners. These rules aren't what I grew up with (yes, in the US, I've never left the country), seem to be different every time I hear them, and usually keep creeping higher. I just never know what to tip, so it's either fast food and no tip, or go a bit hungry until I can get home.