If you are getting a significant chunk of someone's time and labor, but not paying them enough to live well, that seems like the definition of exploitation. If you can't pay a living wage, your company should go out of business - it's not helping society, and it's sucking up air that could be used by other companies that CAN pay their workers a livable wage.
Specifically in the case of walmart, they CAN pay their employees a living wage. They drain about 6-7 billion from taxpayers (1) by way of workers on assistance. From 2006-2020 walmart has made over 10 billion/year every year except two (9ish billion and 6ish billion) (2)
Who really should front the bill for low earners to live above poverty, and why?