From a detailed review
"Apple has come to dominate in mobile SoCs. In a lot of ways, though, Qualcomm has been an easy dragon to slay. Should Apple choose to go custom silicon route on the Mac platform, Intel will not be quite as easy to beat. But the rapid iteration that has led to the iPad Pro's A12X makes a compelling case that it's possible.Apple walks Ars through the iPad Pro’s A12X system on a chip | Ars Technica
Apple won't talk about its future plans, of course. You could say that's all in the future, but when you have a 7nm tablet chip that rivals the CPU and graphics performance of most laptops and beats two out of five of the modern gaming consoles on the market with no fan at barely over a pound and less than a quarter-inch thick... it feels a bit like at least some particular future is now."