It’s the crossborder settlement which they charge for, which I don’t think is crazy, as it just reflects the underlying costs Stripe must be incurring themselves.
As someone who ran a business in multiple countries, the bank always charged similar fees for these transfers between accounts. Stripe letting me settle directly in the account where I want the money to land, rather than me having to log in to my bank and initiating a transfer manually where fees are ~the same is definitely a better option, which I’m happy they offer.