The difference is that it’s not designed in China. Foxconn certainly provides input to the manufacturing process, but the engineers in the US keep the quality bar high.

Nope. Anyone can build iPhone quality devices in China. They will just cost as much as an iPhone.

What happpens is that there is a demand for cheap crap so that's what they design in China. If you were willing to pay Apple level prices for a Chinese brand they'd build you Apple level quality.

If you were willing to pay Apple-level prices for a Chinese brand, provide significant oversight at every step of the process, and constantly quality check every batch delivered, then you might get Apple-level quality.

What do you think Apple does to get that level of quality? :)

It's simple. It costs.