Most of my apple kit is manufactured in China, and is as good a build quality of any electronics I own, as far as I can tell.
It seems that the quality is determined by the design; that is, the Chinese manufactures build it as awesomely or as cheaply as you tell them to.
The fear is that unscrupulous manufacturers will substitute inferior inputs, I suppose, but it appears that, at least for premium brands like Apple and Lenovo, that is not happening. As for labor inputs and standards, well, scruples seem to be lax everywhere but Germany. Personally, I try to be aware of the social impacts of the products I buy, but when I have purchased stuff produced under questionable social conditions, said stuff has never seemed to have suffered any performance degradation. Rather, unfortunately, the opposite is sometimes the case.