It used to be quite the opposite. Tipping was big in Europe but not in the US.
That changed with Prohibition. When alcohol was banned, there was suddenly a large whole in the bottom line of restaurants across the US. They turned to having a tipped staff to stay open.
Sadly, when it was repealed, tipping stayed. It was since inflated from 10% to 15% to now over 20%.
Some have tried to get rid of it, but sadly it hasn’t worked.