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.