But it is necessary for achieving it. Many other policies and behaviours play similar and necessary, but not sufficient, roles. Having been given a mandate, the central bank needs to achieve it. This requires setting out an operationally relevant policy target and ensuring that the institution has the powers to achieve it.
Central bank independence is really just about giving the SARB the institutional freedom to get on with those two things. But, of course, hitting an inflation target is not a simple matter of declaring a target and then browbeating economic actors to set prices and wage demands in line with this target.