Since Wero (that is included in the new initiative) already has a mass from Germany and France, including Spanish and Italian operators more or less locks down something without major competition inside the EU market creating something universally useful that now has a large enough mass to become the defacto standard.

Notably absent is Swish (that is probably the oldest banking-backed mobile payment app in Europe operating since 2012), they were kind-of-interested in cross-transactions when the Vipps/Mobilepay merger also connected with some Finnish party but iirc nothing happend.

No idea if it was due to hubris and protecting their own market or feeling that technology matching was problematic (Swish has a bunch of features like corporate reciving/payouts, payment-requests,birthday cards, receiver identification,etc that might or might not mesh well with foreign providers).