John Oliver did a video a few days ago [1] about some of the problems that truckers face. I can see where having an employer and a fixed salary, even if it's from Walmart, might be preferable to having to deal being an independent trucker.
Among the things that independent truckers have to put up with is that if they show up to pick up or drop off a load and it isn't ready, they just have to sit there and wait, and they're not compensated for their time. If we're looking at industry practices in need of reform, that would be one.