If we are taking about Stripe, we should mention the silent competitor barely anyone talks or knows about outside the payments industry: Adyen. Stripe’s current, (private) valuation is $36B. Developers love them. Adyen’s current, public valuation is $43B (they IPO’d amongst little press coverage). Most developers don’t know about them. So what is the difference? Market strategy. Adyen only goes after large businesses…
AMEX and Discover's transaction costs are a percent higher on Adyen, and I can't actually tell what Mastercard or Visa will charge since it is obfuscated. The cherry on top is the FAQ at the bottom that describes what interchange++ is but doesn't actually tell you a range of fees that it can be. I guess it's cool to see in detail all the middle men taking a cut of my revenue, but I'm way more concerned about the actual amount that is being taken out ahead of time instead of it being a surprise for every transaction.
[0] https://www.adyen.com/pricing?navItem=northamerica [1] https://stripe.com/pricing