It depends on your definition of “legit business.” Just paraphrasing what others have said, but yeah, they are. I’ve ordered from them lots of times, and almost always got what I ordered.
Does that mean they have customer service and speed like Amazon.com or walmart.com? Nope. It’s different than what the average U.S. consumer has come to expect (dunno where you are). Some people can deal with that. But not everybody can make the shift to Chinese business practices and the language barrier.