Ali Express does over a hundred billion dollars a quarter in Gross Merchandise Volume. That's 5x the size of Ebay. And they have a government behind them which is actively working to undermine US business in favor of its' own China isn't going to do anything about it, and apparently neither will we.
The informed will avoid sites like this, the un-informed who should know 'if it's too good to be true', will flock, spend and be suckered !
Actually, as China is moving to a service economy and further up the food chain (designing the phones instead of just selling them) they ARE becoming more respectful of intellectual property rights. But they have so far to go and are starting from such a low level, it will take a long time to make appreciable progress.