Well there are obvious reasons price for one, a A13 Chip might cost apple $25 to produce which is far cheaper than Intel Core i9-9900K which would cost us $479

Well there are obvious reasons price for one, a A13 Chip might cost apple $25 to produce which is far cheaper than Intel Core i9-9900K which would cost us $479 even for OEM's at bulk prices it would cost them south if $420, even if Apple produces 4 times as dense as chip as A13 which is already quite dense at 8.5 billion transistors it would not cost them what Intel is charging. And Intel has been overcharging for a decade as is evident from AMD's processor pricing. Also A13 is an energy efficient product at 7nm compared to any desktop processor at this time.