As for Apple being fragile, well, all the players in the highest-performance space at all levels right now are dependent on TSMC in Taiwan.
For perspective; I think Apple is fragile insofar as I thnk their inclination is to double down on a trend, just as it becomes over-cooked, and culture goes in the opposite direction. The Macbook Neo, it's cheap, and there's a worldwide recession. I would be unsurprised if Apple took the success of that product to "improve it' by making it more expensive, putting a notch into it, shuffling it higher into the pricerange, when
cheap was literally its only selling point.
To look at the car world by way of metaphor; Ferrari have been going more and more digital with cars, more and more electronic, more and more performance, unheralded performance...
...and what are the customers for supercars and hypercars demanding from makers?
Customers want slower cars, with manual transmission, no hybridisation. Electric supercars are being cancelled, hyper-analogue restomods are the hottest thing in the automotive world. Customers want a visceral experience; a steamtrain they can use on the road.
And Ive now designs a car for Ferrari that's been panned by everyone who already owns a Ferrari, will probably sell some to vulgar new money people, but it'll never become a collector's item, so the financing packages which underpin a lot of supercar sales will collapse for it.
Like Ferrari, Apple is fragile to its own success (and hey, there's Eddie Cue at both companies).
AI is the feature Apple's performance is so good for? But AI is the feature most people HATE in their products, so who is all this performance serving? #NoAI authenticity is the emerging paradigm. In day to day usage, the modern Mac is less capable than it used to be, because modern software has gone so far down the "simple is easier" fallacy, that it's past the inflection point of "less is less".
I suspect KDE, for example, can get good at being user-friendly and covering more people's use cases on existing "obsolete" hardware faster than Apple can become anti-fragile to circumstances. If the EU for example, which is a larger population than the USA, uses competition law to fundamentally break the trying points of Apple's ecosystem (given the political animosity, and Europe's sovereignty push for technology), I think that's existential for Apple.