Immigrants often are expected to work for less money. After all, they usually immigrate from an economically worse country, so they don’t expect to land top tier wages.
You keep filling in minimum wage jobs with an endless supply of immigrants, then there is never a worker shortage and never any incentive to raise the bar. No company needs to compete with higher wages to attract talent. In fact, it can make things worse and cause a race to the bottom… Reducing wages on existing positions until workers quit and just filling it with less skilled workers.