The EU is not perfect, but these kind of black and white comments highlight why it can be slow to align everyone to get on board with an idea. The empty vessle makes the most noise.
The EU has had the plumbing needed for this since at least 2 decades, yet has not managed to create this.
> If developing countries can build one over the course of a decade
What countries are you talking about ? The EU countries have some, we also have instant IBAN transfers without any payment processor, we have PCI compliance in all banks to allow it. This feels like another example of you not knowing what you're talking about when you say 'The EU has had the plumbing needed for this since at least 2 decades, yet has not managed to create this.'.
The foundations to never rely on payment processors is already there, now we need to remove the dependancy on payments like visa and mastercard because of nescessity. And as someone above posted, it in progress, it will be done standardised across the entire EU, in Brazil, it's one country.
Edit : There was also never a demand for it because the EU reasonably assumed it could rely on US partners to cover areas in which the EU didn't focus. Only recently those priorities changed, politics has that effect here of dealing with the most pressing issues and not those that are lobbied for the hardest.