The problem isn't just getting something that works across all European countries. It's getting something that works globally.
While we may make most of our payments within EU, basically everyone still occasionally pays for something outside of EU, either online or when they travel. This means if the new thing only works in EU, every European will still need and have a MasterCard/Visa even if they use it less often than before.
This is still a massive amount of leverage - MC/Visa still have the ability to block payments made from EU citizens/companies to outside.
You can buy things from your local Amazon or national equivalent that come from outside using this systems, so, you are not so restricted to EU sellers.
I suppose the most problematic would be traveling. I recently when outside the EU and was surprise how smooth the process was using my Visa card, to the point I didn't use any local currency.
On the other hand, I recently buy books from the UK and it get stuck for two weeks in customs, and it had nothing to do with the payment platform. I had not realized how difficult is to import something from outside the EU, even for personal use.
Many (most? all?) of the payment systems I’ve used over the years can interop with Visa or Maestro. Case in point: my Bancontact cards can pay in any Belgian business even if they can’t afford the better machines that do VISA, but my card also has the VISA logo. Same in Portugal and Germany.
If you can give merchants something that costs them only 0.1% in interchange fees, you can be pretty certain they’d jump on it.
If you build it on IBAN it already works everywhere.
Also European merchants who need to accept payments from non-Europeans need to accept Visa and Mastercard.
Of course but they can support an EU standard as well. It's not mutually exclusive.
The big benefit is that all internal EU card transactions are no longer routed via US companies which is quite ridiculous.
Internal transactions all over the world are routed through US companies. I have paid using Visa or Mastercard at some point in Australia, Indonesia, India, Frnce, Sri Lanka, Singapore, Dubai.....
its not exclusive, but there is a problem with network effects. From the point of view of a business why should they add support for a new payment system no one users, from the point of view of consumers why should they sign up to a new system that no one accepts?
As I said in another comment the most likely alternative is a more decentralised system that all countries/currency blocks that want sovereign payments can get behind.
It's a problem for two reasons. First of all it means American companies get access to a lot of privileged information. Secondly, them pushing foreign morals eg sexual content or services being blocked.
If there were an EU card system id certainly sign up for it and demand from vendors that they support it. I don't want my data ending up in America especially these days.
The network effect will work out fine because we have reasons to want it.
Its a problem but a global one, not merely a European one.
Network effects are very powerful.
You might care enough about privacy but most people have given up.