Re: Not enough
"As the regulations and conditions vary with national laws, it would make sense not to attempt to generalize for every location, but instead to take them separately. As such, since the U.S. is one of Amazon's largest markets, it's not unreasonable to write about that one in its own article with additional articles about other countries to follow if interesting things are found."
On the other hand, the USA is a federation of 50 different "countries", each with their own local labour laws and employment rights, so taking only 5 cases from a widespread geographic area is a bit like taking a single representative from each of UK, France, Germany, Spain, Italy. (Except, maybe, all being EU members, their employment laws and conditions are probably more similar than some random group of US States.)