What about police officer at traffic stop? Or judge or prosecutor prosecuting you? Aren't those also pretty personalized services? Why are they different?

Tipping them could be misconstrued as bribery.

I still don't understand where we are supposed to draw the line here.

Is it OK to tip a therapist or a doctor?

General rule to help you out: If you need a 4yr degree to do a job, you don’t get tips.

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.

So much work to keep an outdated tradition alive.