I'm not sure about the out-dated role of aircraft carriers at all. They still have enormous symbolic value in the game that's being played. Attacking one of these big and slow moving American naval targets, though tempting, is an enormous step for any foreign power. Attack and destroy a US aircraft carrier is like asking to be nuked in reply, as the reaction in the United States to such an act, would be off the scale. Essentially the Americans put these huge ships in harms way as a kind of 'dare', daring anyone to touch them, knowing the kind of response such an act would trigger.