I grew up in a restaurant in the US. Tipping is a counterintuitive evolution in wages, I’ll probably dig in more.

Anecdotally, a waitress could easily earn more than minimum wage during a shift. Sometimes easy clearing $100 when minimum wage was $7/hr (it was $2.15/hr for wait staff). Add to that the tip reporting was lax and no there’s no tax on tips, waiting is on par with minimum wage.

An interesting side effect is that adding waitstaff is marginal cost to an operator.