Delta is back on top. Perennial strong competitor Alaska is right behind though they had numerous operational problems. Southwest comes in third – even though they completely failed over the holidays (recency bias!) and their on-time performance frequently lags with shorter turn times for aircraft. JetBlue is consistently an operational mess, here worse than Spirit and Frontier.
While I expect Delta to tout its win, note the subheading is “No one airline had a particularly good year.”