just my opinion/exp - I barely even consider Australia as 'another country' from my work in HR/Recruitment - people flit between the two so easily.
Like many families I have direct relatives born both countries - incl one Oz grandparent, two nieces, one nephew - and they (the young ones) have all been across/back for work at one stage, two are back to NZ one in Oz. Also have nephews born Sarawak (plus niece), Edinburgh . . . dual passports galore.
I've worked in Oz twice, Perth and Sydney. Both good places if you want big city life - I decided I didn't. As with any place, only 'good' if you have a good living situation, job/income to suit needs, friends, social life imo.
Equally, some people would be unhappy anywhere.