I'm a California restaurant operator preparing for the $20-an-hour fast-food wage by trimming hours, eliminating employee vacation, and raising menu prices
Based on my experience in jobs with tipping, the people who don't get tips quit and do something else and the ones that get good tips like to complain that all servers would get less if there was a reasonable minimum wage because they assume everyone else gets the same.
Note that there is constant turnover in tipping positions because most people don't make good tips.