What I really don't understand about these two is that they get to set the rate very often. They are independent and thus should be able to set rate where they do not need tips. It is like being consultant setting hourly rate and then expect still getting some extra...
What about police officer at traffic stop? Or judge or prosecutor prosecuting you? Aren't those also pretty personalized services? Why are they different?
Plus it has to be a "personalized" service, apparently?
I was genuinely curious so I googled where I'm supposed to tip and how much. It seems like there are an awful lot of rules about tipping, and they don't follow a clear, consistent pattern, not even for when to do it, e.g. before or after receiving a service.