We don't even have new Zen 3 mobile chips yet if they are anything like the New Desktop parts we just got last week then everything Apple just put out is FUBAR.
I'm hoping Zen 3 delivers because 4000 mobile chips shows great promise but is not available in anything premium (MacBook pro level) and has supply issues.
That being said Apple has an advantage in that they control the entire stack and on the power efficiency side of things they have experience with mobile CPU design, they can do stuff like heterogeneous cores and can optimise for it throughout the stack, I think it would be challenging for x86 to do the same.
