The situation you advocate for is common practice in many countries.
I'm likely missing nuances, but to me it seems that the key culprit is minimum wage laws in many US states having an exception for restaurant personnel. If a minimum wage was unconditional and high enough to live from, you wouldn't need tips to survive.
The US has a big cultural expectation of tipping, so even though the entire west coast, NYC, Chicago, and Washington DC have gotten rid of lower tipped minimum wages and effectively increased wages for waitstaff, almost all people still tip in all of those places. Even more, over the years, the standard tip amount has moved from 10% to 15% to now what seems like wide support for 20%. Not to mention that large portions of the population now tip for non waited transactions too.
It gets even crazier when you go out with people and they look at you like you’re cheap for calculating tip on pre tax amounts. There’s a lot of pride in the US for tipping, as if it’s a status symbol.
I'm likely missing nuances, but to me it seems that the key culprit is minimum wage laws in many US states having an exception for restaurant personnel. If a minimum wage was unconditional and high enough to live from, you wouldn't need tips to survive.