TSMC manufactures the silicon for nearly all of the current generation high end silicon. The only exceptions I've been able to find are, naturally, Intel's CPU lineup (which has nothing to do with AI) (and, to be clear, Intel Arc is also manufactured by TSMC), and the Snapdragon 8cxg3, which is manufactured by Samsung; and the "advanced-ness" of the 8cxg3 is pretty miserable compared to A16, M2, RTX 4000, RDNA3, or Tensor Processing Units.
Apple has purchased the entirety of TSMC's 3nm production for the next 1 to 2 years. They can do that, and can continue to do that, because they have a ton of money. They have a ton of money for buying chips because there isn't some crazy business middle-logic justifying the cost of these chips' performance; they buy chips, they sell chips to consumers. In comparison, literally zero other customers of TSMC derive the majority of their hardware revenue from selling to consumers. Companies like Nvidia make some money this way, but most of their money goes to data center sales, which has their own business justification for buying them which fluctuates (ChatGPT subscriptions? training models? is the past model good enough? etc).
Apple has purchased the entirety of TSMC's 3nm production for the next 1 to 2 years. They can do that, and can continue to do that, because they have a ton of money. They have a ton of money for buying chips because there isn't some crazy business middle-logic justifying the cost of these chips' performance; they buy chips, they sell chips to consumers. In comparison, literally zero other customers of TSMC derive the majority of their hardware revenue from selling to consumers. Companies like Nvidia make some money this way, but most of their money goes to data center sales, which has their own business justification for buying them which fluctuates (ChatGPT subscriptions? training models? is the past model good enough? etc).