Goldman Sachs, the bank Apple uses to provide banking products, does not offer consumer banking services outside the US. Banking is a very regulated industry, so does not translate well across borders. This is why having (say) a TD Bank account in Canada does not mean that you can transparently withdraw from it from a TD Bank US branch; you have to have a separate US account, and transfer the funds between.

Apple will only offer its card (and now savings account) outside the US if and when it can find a partner that is willing to do what it has persuaded Goldman Sachs to provide in the US, the high interest rate we're discussing being one example, and it thinks doing so will be worthwhile in terms of addressable market and potential profit. This means that a) most countries will never get Apple financial products, and b) it's quite possible that Apple Card will never be available outside the US, not even in fellow high-income countries with comparable iPhone adoption rates.

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