The sheer number of planes combined with the difficulty shooting them down means many battles now see you spending most of your time firing at planes - this is not what the game should be, at all. It needs to be fixed asap. Fixes might include:

Reducing the number of scout planes ships have, should be no more than 2.

Increasing velocity of AA rounds, a lot.

Increasing power of base AA defence, a lot.

Increasing splash size of AA rounds.

Increasing dmg of AA rounds.

Automating AA fire, with unlimited ammo.