Doing more things isn't necessarily a good thing, doing the right things is.
AMD has a ruthless focus on a couple of markets, a competitive product and clear leadship.
That makes them a threat whatever the headcount.
If EPYC starts gaining ground in the high margin/high volume server market then Intel has to double down and they might, the Core architecture was a response to the AMD64 and a good one.
They aren't out the fight but they are taking a few hits at the moment .
There is not a lot of vertical integration in Apple's physical supply chain. Screens are sourced from Samsung (or have been last time I checked), phones are assbled by Foxxcon (same as above, might have changed).
Managing all that is what set's Apple appart from others. Besides brand, design and such. I'm in no position to judge the software part.