I'm also curious about this. And, even moreso - did apple just start designing chips from scratch or did they buy someone who already had some cutting edge technology? Its hard to believe that they're beating everyone just out of nowhere...
But Anandtech had articles as far back as the A12 7 years ago where it was competing with the intel chips of the era
A secondhand link because anandtech is restructured now unfortunately https://appleinsider.com/articles/18/10/05/apples-a12-bionic...
…because he left to work on the chips.
A huge number of them were Iranian.
Apple is a vertical integration company and the CPU/GPU in their devices was a clear sore spot of relying on external vendors they did not like.
You can see their lead continuing and growing with things like their new modem used in some iPhones