The ACCC record is not covered in glory. Relatively toothless and they have to prove anti-competitive behaviour versus QF just giving the customer what they want, i.e, cheap seats and plenty of them. On routes where there is no V2 - its open slather and we will pay dearly.
Just look at the ACCC's complete lack success on the price of fuel at the bowser if you need an example of their inability to have much influence on the market.