Cash and cash equivalents is the line on the balance sheet and includes things like T-Bills and other low-risk investments. Apple almost certainly does better than inflation and regardless, it's completely normal treasury management to return ~0% since if your shareholders wanted exposure to riskier assets, they'd buy those assets with their own money.
Yes, they could, however the point made above is valid - if they did that, they'd have to pay a chink of US corporate tax on it, and unless they have a use for it in the US, that'd be analogous to throwing money away.
In recent years, Apple has been taking out big loans in the US (or selling bods - same effect) collateralized by their overseas cash equivalents whenever they need an infusion of USD. Paying 2% interest is much cheaper than paying 10-15x that in taxes.
Technically, a bank has a lot of rules to follow, and I do not think they want to get into that business (yet).
But then they'd have a massive tax bill.
