You're a customer, you don't have a "job". You have a bill for goods and services. You choose which goods and services you purchase. The bill presented to you at an American restaurant is calculated based on sub-minimum wages due to the tipping convention. There are some restaurants which calculate their bill with a living wage, and do not solicit tips, and this is reflected in higher prices.

By patronizing a restaurant that pays based on tipped wages, and not paying a tip, you are saving money by exploiting the system at the literal expense of the employee. Choose not to purchase from companies that secure low prices by exploitation, or write your representative to end the tipped wage laws that perpetuate that exploitation.

Just remember that the only one who suffers when you didn't tip a tipped-wage worker, is the worker.