Was Australia needed at Gallipoli in World War I?

Yes Australia was needed. The ill-advised assault on Gallipoli ended in defeat, thus achieving none of its objectives. In fact, it strengthened the position of the Germans by bring Turkey into the war on the German side. Without the joint Australia and New Zealand Army Corps (ANZAC) the allied defeat at Gallipoli would have occurred sooner. To that extent, Australia was needed. But the decision to attack Turkey was ill-advised, and the attack poorly planned and, in some ways, poorly executed.