> More importantly, there is some actual work being done or service rendered for the tip.
No, that isn’t for the tip, that is literally the job they are paid to do by their employer. Choosing to tip should only be if they have gone above and beyond what you would expect. I’m from the UK and find the US tipping culture bizzare and stressful - I had truly terrible service in a restaurant in New York once and they literally chased me to the door when they realised I hadn’t tipped and threatened to call the police if I didn’t tip him at least 10%.