The difficulty is that tipped employees, in some parts of the United States, can (and do) make as little as $2.13/hr. Laws ostensibly exist to ensure that tipped employees make minimum wage (federally mandated at $7.25/hr), but, due to a variety of factors, this isn’t always the case (to say nothing of the fact that $7.25/hr is hardly a living wage).
I spent 25+ years in food service. It was a lot of fun and seemingly good money when I was younger. Now that I’m 40, things like dependable pay and benefits trump the fun I had waiting tables and bartending all those years.