Is that true? Polling the API might be too much, but I would expect Stripe to be able to handle a few GETs for every payment they take, even big companies will probably only be taking ~1-10k payments/second, doubling or tripling that isn't much. And ingesting webhooks for payment is necessary to be able to perform access control or whatever is necessary for the business to function. Conversely, $0.03 of margin to patch over bad engineering is quite a lot of margin for some types of business.

Lower tech businesses perhaps, but most of them probably aren't doing data analysis anyway.