Earlier quoted context omitted.
That's true for literally every aspect of every job, though, so it seems like a pointless thing to say unless there's some indication they're actually abusing this.
We can create laws without an indication of previous abuse. We can regulate not just because we have indicators of abuse but because we can imagine potential abuse. We don't give toddlers handguns because our pre-frontal cortex allows us the foresight to see that it's a bad idea -- we don't need to actually wait and see if one toddler shoots another.
Like, if Walmart was offering employees extra money to dispose of toxic waste or collect debts from delinquent customers or something, I'd see a huge potential for abuse and wouldn't consider it to be at all a good idea. Those things need special training and the potential for problems is high.
But this is package delivery. It's a relatively unskilled, low-end job. Its abuse potential seems to be to be on the same level as the abuse potential of, say, lifting boxes, or stocking shelves, or mopping floors. "Walmart pays people to stock shelves" wouldn't get anyone up in arms, so why would this?