> Why is Apple's market cap so much higher than Microsoft and Alphabet?
Because Apple brings in more revenue than Google ( 50% more ) and MSFT ( 100% more ) and they bring in more income than google and msft.
> Their businesses are bulletproof.
Apple has people tied to their entire stack ( hardware, OS, apps, store, etc ). I'd say apple's business is more bulletproof than google or microsoft.
> Apple on the other hand is completely dependant on China and you never know when a supplier drops the ball somewhere in the chain.
They are tied to the largest economy in the world? An economy that is set to double or triple the size of the US economy in the next few decades?
It's amazing what Apple has done. Nobody 20 years ago would have predicted they'd make $200 billion more in revenue than microsoft.