I wrote about tipping more than 30 years ago in several magazines and newsletters. I've written four blogs on the subject over the past 15 years. Nothing I said then has made a dent on any mind whatsoever (in case you want to point to several areas of my intellectual impotence).
The subject has come up again. A good friend, and his family, stayed with us for a week in Tokyo. He was appropriately stunned by the absence of tipping. Complete absence. Ordinary meals in Japan are much cheaper than in the U.S. without tips. The business lunch with 'specials' is the best priced meal on the planet.
The subject of tips and tipping often comes up and no one seems to be conscious of the fact that tips are not a way to reward or punish service workers; they are a remnant of a training tool for slaves and servants. And a way to reinforce the slave-servant-master hierarchy.
Every job that involves tips was formerly done by slaves and servants. Food service, taxi and livery service, baggage handling, hair cutting, etc. All the places where we don't tip service people are where the service was formerly provided by skilled workers: gasoline stations and auto repair workers, plumbers, electricians, carpenters, dentists, lawyers, retail clerks, firemen, policemen, ambulance workers, nurses, etc.
Tips are a vestige of slavery.
Japan is proof. They never had slaves. They did have many people we would call 'servants' but the relationship was familial.
The people who should know most about tipping in the U.S. are blacks. But they don't.