> why EU doesn’t try and develop a homegrown card provider? It would provide exactly what MC/Visa does

They have. A combination of petty squabbling and the lack of any real value proposition has always killed it. To have any chance of succeeding in the EU a new system needs to be something that no-one currently provides, because consumers are unlikely to adopt something that isn't clearly better than what they currently have, but more importantly no EU country is going to adopt a different EU country's system.