Basically most of the world except Noth America pay their waiters wages that don't depend on tips. Sure some places allow additional tipping, but it's not a mandatory fee and the workers don't have to get it to make a living.
Replacing tipping with a 20% mandatory service charge -- tried many times here -- results in the employees earning less money, empirically. Eliminating tipping is unpopular with employees since it is effectively a pay cut.
Proponents of "no tipping" policies in the US are not going to be successful until they address the elephant in the room of reduced pay for employees. Unlike in Europe, US employees know how much money they earn with tipping.
It's about the social safety net, not just about raw cash.
The same waiter in most European countries would have health insurance even after being fired, for example.
[0]: https://www.seattle.gov/laborstandards/ordinances/minimum-wa...
That may true in raw numbers but is it still true when you consider that a European worker will have coverage for health, retirement, paid annual leave, paid medical leave, will have access to unemployment benefits, will get subsidised lunches (in some countries) and will be protected by laws that enforce overtime pay and their rights to not be fired without justifiable cause.
Raw numbers are not the full picture.
