So what? The SEPA shift was also a compat nightmare - even worse than in the US I'd say. 34 countries with each having their own system of bank and account IDs that all had to be rolled over into one common system, and banks now being allowed only one day of delay (which used to be up to a week for international).
The EEA covers over 500M people, way more than the US does, with way more languages. It's not impossible to do such a migration, the difference is that EU legislators were fed up with the brokenness and forced the migration via regulation while the US government believes that "the market will fix everything". No it will not, the market will only deliver what is the lowest acceptable effort.
