10 years ago there was USAirways and Continental, and Northwest a little before that. Reduced competition buoys the remaining survivors, but the history of bankruptcies in the industry certainly lends quite a bit of doubt towards your assumption.
The assumption is that as they become fewer, the ones that remain gain staying power. Which is why I excepted JetBlue since they could get sold or fail, I think they are hoping their Spirit purchase goes through.
Crazy to think JetBlue wanting Spirit. I remember when JetBlue started, their goal was to provide a better experience than all the other airlines. It is really a cutthroat business. Virgin Airlines had to be folded into Alaska too.
I think in many cases they are just buying routes/gates. If the airports are maxed out in gates how is the company supposed to grow? And a company that doesn’t grow is a “bad” company, or at least management doesn’t get paid as well for high profitability/low growth it seems