I agree with you to a certain point. AC is a power projection weapon, not a strategic weapon. The subs will be the last remaining ships "sailing" when all the surface fleets are wiped out. This is because the noisiest sub is more quiet than the most quiet surface ship. If you can hear them first before they can hear you, the battle is over.
However, battle carrier group is still useful when fighting a none strategic war. Basically, a none nuclear war. So there is still value in AC groups as not all wars are world ending wars.
My query was specifically about the Indian ACCs.
Once we accept that they are for air power projection, then the question is against whom? Pakistan is covered by our land forces. As for the Chinese, the fleets will have to enter Pacific even for projecting what rudimentary power they have. Can you do that with 3 ACCs of which only one will be operational at any time? And will that pacific entry against China be anything more than a heroic, but futile and fatal gesture.
The only use I can think of is for blocking the Straits of Malacca during hostilities with China. Obviously India cannot do it effectively by itself, and I suspect that it will use its ships to cooperate with US fleet. Which means that it is actually the US which is instigating and helping India towards true blue water capability which is more in America's than India's interests.
No harm in getting Blue Water capability if you can afford it. But India has far more pressing priorities for defense funds.