Having a domestic payment scheme isn't an issue regarding card adoption. I'd even argue that offering a cheap domestic payment scheme is fundamental to adoption

Having a domestic payment scheme isn't an issue regarding card adoption. I'd even argue that offering a cheap domestic payment scheme is fundamental to adoption on the merchant side. See the situation in France for instance. All EC cards issued by German banks are co-branded, it used to be only Maestro, nowadays mostly V-pay. They do work fine abroad. (V-pay a bit less so than Maestro, but that's not a bug, that's a feature, skimming is a big issue in big German cities, that's why a lot of banks switched to V-pay)