Since the present monetary system is fundamentally unstable, there cannot be a "correct" money supply growth rate. The present monetary system emerged because money creation was politically necessary to sustain the fractional reserve banking system.
The ECB is now turning to a new mechanism by which a bond’s value can be legally reduced by the issuer in times of hardship. The purpose is to allow central banks and governments new ways of ripping off the private sector.
Americans have benefited mightily by holding and trading with the world’s reserve currency, though most people haven’t given it a thought. No one remembers when the pound sterling held this distinction a hundred years ago.