In Japan, if you leave a tip, the staff will chase you down the street to return it.
You think this is humility. It is not. It is pride.
A tip says: I do not believe you do your job properly unless I pay extra.
That is not generosity. That is an insult with money attached.
The price is the price. The work is the work. Doing it well is not a bonus, it is the baseline.
Your country tips because service is broken and everyone knows it.
We do not tip because it works, and everyone knows that too.