China only makes $8 from an iPhone – and that's why Trump's trade war is futile

I don't think it is about the $8.

Previously, China outsourced social and ecological cost of producing iPhones and other technology. That outsourcing is not covered in the price.

Recent political changes in China such as environmental requirements cut the key profit: the outsourcing.

If the US has the choice to either have a factory in China, or have a factory with roughly the same standards at home, the trade-offs are different: you might want the jobs at home then (given that the wages are competitive, which they currently are not).