It's interesting to dig into the QF business. I know everyone creates a really rosy picture, financially. They are doing great domestically, but just OK internationally.
QF do have a stellar domestic business, with EBIT of ~ $700m, and operating margins averaging 11% over last 5 years. Very good for an airline. They have done something right to be the dominant player in a nice duopoly. This contrasts to the struggles during capacity war when their EBIT went as low as $30m... and to quote their annual report ... "Market capacity increases above demand between 2012 and 2014 put intense pressure on yields and reduced the domestic profit pool " . They are lauded far and wide for their turnaround, but the ceasefire in the capacity war was probably a the key factor in their turnaround.
International, financially suffers from much more intense competition, and thus only has had operating margins averaging 6% over last 5 years. With recent capacity increases, last year their EBIT of $285m , and 3.8% operating margin down from $570m and 8.9% in 2016 (when aviation fuel was at its lowest price. Worst performance 2014, huge losses, jet fuel $120USD/barrel,best 2016, $50USD/barrel, FY19 back up to $80 USD/barrel, and EBIT/margins suffered. One would suggest their success internationally is primarily tied to fuel prices, and investments in expansion in international may be more difficult to pull off.
Jetstar has margin of arond 10% and brings in more EBIT than international, whilst loyalty is the standout, as we all know, $370m EBIT @ ~22% margin.
Overall, well run, a slick marketing machine, leveraging fully the financial benefits of a cosy domestic duopoly (reflected in domestic, loyalty and Jetstar).