It's funny how we have so many checks and balances for welfare recipients, but for insider trading, wage underpayments or tax evasion, it's practically self-reporting.Most of the Centrelink red tape would cost more than it saves would be my guess.
For the handful of people who manage to rip off welfare, we'd be spending a staggering amount more on bureaucracy.
Better to simply it and let the ATO pick it up, and if a tiny number of people still rip the government off for their welfare payment, so be it. It'll save money and those staff resources can be redeployed in far more useful ways.