You are right, Qantas makes money due to barriers of entry,...

You are right, Qantas makes money due to barriers of entry, duopoly, customer loyalty, government support. Shareholders get peanuts. This is possible in a high volume low interest rate environment, cheap jet fuels.
You are also wrong. Low airfares are unsustainable (long term 5 to 20 year cycle) due to the bottoming out of the interest rate cycle, fallout in oil investment (future long term price increases back to $100barrel), oversupplied airlines market, high capex aircraft replacement on high volume business model.

Airfare prices must rise long term. Thus, average wage, business/government travel spending must rise long term.

I can't see a wages boom anytime soon.