Amazing. I wonder why? Amazon must have insane deals with the credit cards. This must be to access some tech that amazon doesn’t want to replicate for some small slice of its business - maybe on the fraud side.
I bet Amazon is only using Stripe for a small slice of their payments to cover gaps in their own payments stack. I'm sure it's worth it for them to be able to take payments at a higher rate than not be able to take payments at all. That's just a back-end optimization they can handle later.
I don't know what slice that is, but there's plenty of reasons you might go with a more expensive provider. Maybe they support some piece of technology you don't (like Apple or Google pay in browsers), or can process for a card type you can't (like one of the country-specific debit card schemes like EFTPOS in AU or Interac in CA), or just are set up to process payments in some country that Amazon doesn't have infrastructure set up yet. A quick google shows Amazon launched in India and Japan in 2017, so maybe one of those markets had some quirk they didn't want to bother supporting on their own until payment volumes got up.
I would imagine that they have an integration with dozens of providers. It makes sense to spread it out so your business cannot be bullied by any single third party dependency and you can pit them against each other to get favorable terms across the board.
