if you have enough bombers you can fly ground support missions to destroy the org of any opposing troops really quickly, otherwise battles with many divisions involved can take forever. then when the enemy is retrating you switch to ground attack missions to target enemy strenght, or whats left of it. if done right you can destroy vast amounts of enemy strength - it is a big exploit IMO. however, total air dominance was crucial for the western allies and many german troops where hit bad in the march to the front so they could no longer fight.
but if you look at the overall significance of air power in an armed conflict it has not lived up to the high expectations that leaders had when air fleets came of age. so IRL air power is important to win battles on a tactical level but its strategic use is rather limited - it cannot win a war for you by itself.
I once played a game as the UK where I focussed heavily on strategic bombers (no new ground troops or ships, only airplanes). By the time Germany was done with Poland their IC was so low they didn't even try to invade the Low Countries. A year after the war started I landed British and French troops via the Baltic and the German defences cumbled without much of a fight.
So you can win a war by air, if the conditions are right and you are prepared to go all out.
Air superiority is very importand!They are two levels of view:strategical and tactical level! You can destroy industry and resources with stategic bombers on strategic bombing" mission,this will reduce the IC,TC and resurces.Is not very impressive at first sight but in condition of total air superiority can be quite efective;but you need to have patience to see the results(1-2 years).For tactical level see the thread up!!!!
Playing as the Soviet Union, CAS is about the only thing I can use to keep the Germans at bay until "The Great Patriotic War" event fires and I build up a 3:2:1 ratio of superiority in infantry, and armour, over the Wehrmacht