I find it funny that everyone is blaming the SkyMiles changes. As if pissing off a small group of people that somehow feel entitled to some "benefits" because they fly 30 times a year.
This is a long coming. Maybe the post pandemic demand is leveling out. Maybe people are finding their budgets to be a little more tight and therefore can't afford to fly Delta when there are other options for cheaper. Maybe they are feeling the effects of the outrageous amount of money they are paying their pilots. Whatever it is, this is a very cyclical industry. AA had a loss this past quarter.