The long and short of your assessment is:-
- We can do with a much smaller Army.
- Airpower is enough to win the war on the ground.
I partly agree with your first point. We have an Infantry-heavy Army. We could mechanise more of our soldiers, especially in the plains and deserts. But we can't erase our past. Before Gen Sunderji, we were completely Infantry centered and in a defensive mindset. Change has to be gradual. Militaries tend to be conservative, its in their nature. Given our past of heavy reliance on Infantry, we can't wish away large number of Light Infantry Battalions deployed in plains and deserts, which is prime tank country. The change is there. Its slow. Can be faster.
But we can't do without Light Infantry in the Himalayas. Nothing rules the mountains the way a strong combination of Light Infantry and Artillery does.
As for airpower "taking out all tanks of Pakistan", that is pure nonsense. Its a well-established fact (although Air Force Officers world-over try to say otherwise) that Air-power alone does not win wars. Its also true that if you can't win in the air, you can't win on the ground. But there is
absolutely nothing that air power can capture without the Army. And guess which is the only arm that is capable of holding the ground in any Army? Infantry.
Another part of your assessment that does not hold in the real world is the argument that tons of artillery can replace Infantry and Armour. I would not advise for such a move even in cases such as North Korea vs South Korea, where the room for maneuver is limited. So forget that this would actually work in the Indian context, where we have a long border and plenty of room to maneuver.
All what you are saying is the first thing that civilians (including myself) think of when we are new to the world of military strategy and tactics. "Why not just stop making tanks and infantrymen and make fighters, bombers, artillery and missiles instead?" No country in the world fights like that. Give me one real world example of a professional military fighting the kind of war we are preparing to fight with only the tools you mentioned.