A company liquidation is only necessary if the company has doesn’t have sufficient assets to pay all of its creditors in full, i.e. it is insolvent How do I know if my company is insolvent?. If your company has sufficient assets to pay all creditors, then you can simply pay them in full and apply to the Australian Securities and Investments Commission for the company to be de-registered.
There may be other reasons to appoint a Liquidator and these may include:
A dispute with your other directors and or shareholders and effective decisions cannot be made (i.e. you need a Provisional Liquidator appointed What is a Provisional Liquidator
The company has made significant taxable gains and you want to distribute these taxable gains prior to the company being deregistration (i.e. you need a solvent liquidation)