Companies only ever have as many expenses as absolutely necessary, including labour. They can’t function with less people. If they could, they would do it and make more profit. What this does is force these companies to pay people an appropriate wage that doesn’t rely on government subsidies to pad their profits.
If paid local labour is cheaper and more efficient than the alternative (ie: offshoring labour or automation) they will hire people, if the cost of local workers rises then companies will choose any other possible alternative that is better for their bottom line.
ie: If having cashiers is cheaper and more efficient than automated checkout then they will keep hiring cashiers. If you raise the hourly wage plus increase benefits etc then at some point depending on the increase, more automated checkouts would likely replace some cashiers. Some jobs can't be replaced, like a lot of services, but the lower the skill needed to do a job often the easier it is replace the worker.
Go raise costs of company call center employees and watch even more of those jobs ship overseas. Beware unintended consequences of what seems like good actions.