True, but proof-of-work blockchains are a *really* expensive way to achieve the goal.
Bitcoin is based on "proof-of-work", but the banking blockchains are not implemented that way. They are much less computationally expensive. Anyone can mine bitcoins, but the banking blockchains are only accessible (or at least writable) by members of the club. If you don't have a SWIFT code, then you don't have access.