Question: are US banking really this dysfunctional? Where I'm from, a bank consortium already provided unified login services (while banks still have their own websites, as a merchant you only need to integrate the consortium-provided APIs rather than using Plaid) simplifying things.
In the US your public bank account number is effectively a password to debit your account! There’s literally no authorisation at all!
Don't you also need the routing number? How does this differ in other countries or anywhere that checks are used?