There’s more to money than what happens in the checkout line, and that’s where the problems with floating-point math arises. For example, one codebase I’m aware

There’s more to money than what happens in the checkout line, and that’s where the problems with floating-point math arises. For example, one codebase I’m aware of ran into serious problems with line item refunds when currency conversion was involved, IIRC. (“Serious” as in “couldn’t generate a refund that exactly matched the charge on the customer’s original invoice.”)