It's still early days of allowing independent (i.e. apolitical) monetary policy committees from controlling money supply/interest rates, but we are and have been in a unprecedented period of relatively low inflation for the past couple of decades. This is despite the greatest financial crash since the great depression.
I'd say there is good grounds for saying this is a great human invention - although probably not on a par with sanitation.
No the system isn't perfect - it is structurally flawed like all other systems - but it has worked well and the negative side-effects can be managed