Amazon is trying to find smart ways around this. Mostly because their entire business model is around removing payment friction (such as One Click Pay).
One way they will do this is by motivating people to buy gift cards or “top up their balances”. That way you only go through SCA once and potentially use that balance for lots of different payments.
Something else they are doing is called Delegated Authentication. They are going to banks and saying “can I perform the 2-step authentication on your behalf?”. This is because most banks out there have a terrible SCA flow, with an abandonment rate of 20%. Amazon doing it themselves take that down to much lower levels (I’m not allowed to quote their figures)