That could have been overshadowed if they could satisfy a niche. They are neither useful for going to work nor Indy Grabbing. Let's just hope next time the trend turns toward something like that it solves a problem.
I know what you're point seems to be even though you aren't communicating it very well. I do think you're missing the fact that producing goods cheaply does not make you a leader in tech. Besides quick fads like hoverboards or fidget spinners China does not have much traction with actually producing and selling products. Things might be made in China but they are designed by foreign companies and the vast majority of the profit leaves the country.
Hoverboards are originally from China [1] however, most of us have likely learned about them from Kickstarter etc. I think the users of HN would agree that "invention is never a sudden thing". The process for hoverboards has been iterative, of course. I have heard claims of having commercial hoverboards as much as five years before they became household names in the US.
Conceptualization is not making something actually happen, unlike what the patent-trolls want us to believe. IoT was first proposed in the 90s, but did it gain any traction before cheap Chinese prototyping components? This bares the question, is it the West that has made IoT or the East?