That’s not how probabilities work. The market share in the US is P(has iPhone | resident of US), but we’re looking for P(resident of US | has iPhone), which according to Bayes’ law is equal to the market share in the US (see above) times P(resident of US) [aka US pop. / world pop.] divided by P(has iPhone) [aka global market share]. So essentially, while the market share in the US may be twice as high as the global average, the US has fewer than half of all people in the world - making it more likely that the person is not from the US than that they are.
That’s not how probabilities work. The market share in the US is P(has iPhone | resident of US), but we’re looking for P(resident of US | has iPhone), which according to Bayes’ law is equal to the market share in the US (see above) times P(resident of US) [aka US pop. / world pop.] divided by P(has iPhone) [aka global market share]. So essentially, while the market share in the US may be twice as high as the global average, the US has fewer than half of all people in the world - making it more likely that the person is not from the US than that they are.
You left out the English speaking, the bad work conditions, and everything else. Please reread.