First, a point of order. This is a destroyer, not a battleship. Now, on to the central question of your post: An aircraft’s missiles and bombs are indeed a threat to surface combatant ships. But there are many things that ships can do that aircraft cannot. They include, but are not limited to - persistent presence, detailed investigation of potential threats as opposed to simply shooting things, carrying a landing party (the Indian national oil company has contracted to exploit oil/gas fields in dispute with China, and carrying a far greater payload.
Interesting points. Thanks