The slowness and cost of international bank transfers has nothing to do with technology used. We could make a million of such transactions per minute using $10

The slowness and cost of international bank transfers has nothing to do with technology used. We could make a million of such transactions per minute using $1000/month hosted server. We have the technology. The problem is legacy infrastructure and the fact that banks benefit from high fees on international transfers. There is at least one successful business (transferwise) that makes international transfers much cheaper and faster using terribly inefficient work-arounds. If banks were at all motivated to fix the issue, they would, using Java and a database. They don't need blockchain (which, btw, is slower to settle a transaction than updating a record in a database).