The tipping system in the US most vitally applies to food servers, who are paid a criminally paltry amount of $2.13 per hour, a fraction of the still impossibly low federal minimum wage of $7.25 per hour, so that tips are highly necessary for their survival. Tipping system doesn't necessarily need changing, but all workers should make at the very least the federal minimum wage. Minimum wage has not changed since 2009 and needs to be livable, i.e. at least $15 / hour.