Why the Alaska class arrived too late

What was wrong with the Alaska class?

The ships were capable large cruisers, but by 1944 the surface threat to carrier groups had faded; they would have been far more valuable in 1940-42.

The class combined high speed, long range, heavy antiaircraft fire, and 12-inch guns able to dominate enemy cruisers and pocket battleships. By entry into service, however, Iowa-class battleships and screens already covered the carrier groups and the relevant enemy surface threat had declined, making Alaska roughly four years late.