Why is Stripe so interesting? As far as I can tell, they still only offer one payment method, credit cards.

That makes them quite uncompetitive in most countries where credit cards are just one of the many online payment methods, and completely useless in countries where most only payment has already shifted to direct transfers without the cost and hassle of going through credit card companies.

The movement is now towards harmonizing direct payments and mobile payment. Using credit cards for online payment feels so yesterday to me.