When Tim Cook joined Apple in March 1998, the company was sitting on a month's worth of unsold computers. Eighteen months later it was down to two days.
He never designed a product. He built a manufacturing system — and that system made Apple the most valuable company on earth, while tying it to one country so tightly that leaving has taken more than a decade and still isn't finished.
The part most people get wrong: Apple didn't stay in China for cheap labour. Cook said so out loud in December 2017. What Apple needed was tooling engineers — the people who build the machines that build the product. In America, he said, you couldn't fill a room with them. In China you could fill several football fields.
Which is exactly why leaving is so slow. You can build a factory somewhere else in a year. The people who know how to run it take twenty.