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.
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.