Regardless of what happened prior to RA taking over and if there would be a DL or not isn't really knowable. We can argue about it until we're blue in the face. But DL is highly profitable now, and is taking steps to ensure profitability and attempting to end the severe boom and bust cycle that was the hallmark of the airline industry.

The fleet strategy alone is worth millions to DL. Buying planes on the cheap but having top of the industry maintenance allows DL to own the planes and park them when times get bad and capacity needs to go down.

AA just spend billions on a new fleet but when the economy inevitably dips again they're going to be stuck either parking new(ish) planes or taking a huge PRASM hit.