For the line of thought in articles like these, there's no difference if airlines had spend $45B on dividend payouts in the past four years rather than on buybacks.

No, because dividends don't benefit from compounding stock prices.

If you buy back your stock from 20 -> 80 a share vs. having paid out the same amount in dividends, the share buybacks yield a much greater income than dividends, which once paid no longer compound unless individual investors re-invest them.