My ass. If you don't put a dollar in the tip jar for buying a $3 cup of coffee in Los Angeles you get a dirty look. McDonald's? Sure. But then, they don't have tip jars. They also aren't minimum-wage exempt - McDonald's has no servers, nor does Chipotle, nor does Burger King. Pizza Hut? Back when they still had wait staff, they got tipped. The two most revered fast food franchises I know of are Dick's and In'n'Out. Both companies pay their employees very well. Neither allow tipping.One example is coffee shop / fast food workers, who rarely get equivalent of 20% in the tip jar (even adjusted for the many more customers they serve in an hour).
I can't speak for the culture of LA, but I knew people working at a <not-upscale-but-local-and-still-frequently-visited> coffee shop in downtown Berkeley. Split among all of the workers of a shift, it usually came out to a handful of dollars at the end of the day. (Also, hence the TIL comment, since after tips they got <$9/hr)