American here. Sad but true, most American restaurant workers depend on tips to make their daily wage. Restaurants are actually allowed to pay workers LESS than the guaranteed minimum wage because it is assumed that the tips earned while working will make up for the difference in wages.
I understand what you are saying but that does not make sense how could governement allow such thing? its like going to work in a restaurant but you need to hope and beg at the same time no wonder i see so many videos where the waiter/waitress shame the customers for it if they do not tip or tip them less.
Currently in the US, 18-20% tipping is the norm, with exceptional service getting 25% or more. The whole situation for tipping in the US is crazy, because it is simply the bosses passing on the cost of labor to the consumers. And anytime you decide not to tip that much when out in public, you are shamed if you do not mee the public standard set by rich people who intentionally decide to be cheap
18 to 25% is so much if i were there i cannot tip that much i will be broke in few days lol. for the rich people not tipping we cant blame them as well this is more of a law of minimum wages rather than force people to tip more because business owners refuse to pay normal wages to humans its crazy.