because Apple goes in and buys out entire production cycles based on anticipated demand. Most infamously they got a year worth of TSMCs last new node - no one else could have it.

Usually, that gamble pays off, sometimes it does not (cough Apple Vision), and in some cases they get so many QC rejects that they can make an entire new product line on (financially) worthless scrap, that's how the MacBook Neo came to be - a bunch of iPhone SoC's that failed binning, I think in GPU cores.