Unfortunately salaries for service jobs have the assumption of tipping built in. In some states the minimum wage for tipped jobs is lower than the minimum wage for other jobs. So if people don’t tip, the person doing the job is getting screwed.
Federal law requires that the tipped employee be paid at least the regular federal minimum wage. I'm sure various state laws have something similar for when the state doesn't just match the federal minimum wage.
https://www.dol.gov/agencies/whd/fact-sheets/15-tipped-emplo...
There are, of course, plenty varying of ideas about the minimum wage.
I'm sympathetic to this, but surely the customers who don't tip aren't the ones screwing them. It's their employers screwing both them and the customers.
People do want to work, for decent wages, not exploitation and begging via 'tips'.