I wonder if it is in fact easier in a German region than a bank though. A bank has massive compliance complications, where the state insists on rules being met, so their are teams of people trying to make sure no rules being broken, and therefore anti-change. Germany is a Federal system, and the region has law making powers, a bit like a US state. Therefore it can set the rules to make sure migration to a new system happens. If big fixes are not allowed, they have themselves to blame. At a bank it is the state causing the friction.