Geez what a miserable few posts. Air travel is here to stay, recessions come and go and, if there is a recession and if it is sufficiently deep, the leanest will survive.
Australia is in good shape financially, the minerals-based prosperity continues, migration is increasing and people want/need to travel.
No airline, regardless of its size, is immune to collapse particularly if bloated and inefficient (eg: Ansett)
However, Qantas will survive as it has shareholder support. Bonza's loads are healthy (not 'empty') and even if they were, the airline appears flexible enough, with minimal comparative overheads to redeploy to more viable routes.
Virgin, Alliance, Network etc all have the covid-learnt ability to downsize appropriately when needed.
Have watched PPrune since Jetstar, Virgin and Alliance started, would love a buck for each time some miserable Prune expert guaranteed their demise.