Not sure Wero will succeed, but European country-specific mobile payment systems like Swish (Sweden), Vipps (rest of Scandinavia), Bizum (Spain), iDeal (Netherlands), Bluecode (Germany and Austria), Twint (Switzerland), BLIK (Poland) etc. are also working on interconnectivity under the EMPSA association. Combined they already have 110+ million users.
Wero is like a monolith, while EMPSA is more like mobile phone roaming. If I would bet, I would bet on EMPSA.
https://en.wikipedia.org/wiki/European_Mobile_Payment_System...
In Austria EPS is also very commonly used.
Wero is iDeal.
Like sepa, this initiative can be forced by law and made open rather than tanken hostage by large cooperates, which may then exclude parts of the market.