Let me describe my simplistic model of air power in support of ground power.
My view is that ground power is the vital factor and that air power is a force multiplier. I argue this based on the simple observation that ground forces have controlled territory for many millennia before air power was invented.
But air power can make ground power far more effective. Lord knows I'm grateful that American ground forces haven't had to operate under enemy air power or without ample air support since about 1944.
So let me look at four scenarios of friendly power, each assuming that in a mathematical equation, each factor can range from 0 (actually making the situation worse) to perfection of 10. A rating of 1 would basically be neutral, neither helping or hurting as a factor.
The best is when American air power and ground power have factors of 10. They are each the best on the planet and capable of working with each other. As a multiple we have 10 X 10 = 100. Unless the enemy also has the best of each (and more of each as well as better leadership and strategy), things should look pretty good for America in battle.
The worst is when both factors are zero. That is pretty much automatic defeat as the end result of 0 X 0 = 0. But we can still get zero as the result if only one factor is 0.
What if air power is 10 and ground power is 0? Obviously, the ground power makes the effects of air power worse than if it could operate on its own. The ground power is unable to accurately call in air strikes--calling it in on civilian targets or on itself; is unable to exploit air power to go on offense; is unable to even hold its ground long enough for air power to ride to the rescue on defense; is unable to exploit aerial recon; and in fact cannot even protect the air bases that house the air power. The end result is that even excellent air power is unable to control the ground in the absence of ground power.
Even if you simply told the ground power not to get involved in the fight and leave it to the air power, it still would not work because the ground power simply sitting on defense would eventually be defeated and the air bases would eventually be captured. I don't believe an independent air campaign could defeat enemy ground power before friendly ground power collapses.
The only possible way this might work is if the ground factor is truly 1 because the air campaign is conducted from an absolutely secure sanctuary. Air power enthusiasts may believe this scenario subset is possible, but I have never seen an example of this pure air power approach to victory.
Finally, what if air power is 0 and ground power is 10? This scenario makes for a zero result because the air power is counter-productive. Even excellent troops find that horrible air power can't find enemies, can't hit enemies accurately and in a timely fashion, does more damage to friendly troops and civilians, and soaks up resources that would have been better spent on the ground forces.
Yet even in this scenario, if the air power is grounded so it can't do a lot of harm, you at least get the air power closer to 1 as a factor (but not all the way to 1 because resources are still uselessly spent on the air power). But the ground power can be close to 10.
If the enemy doesn't have air power and even a slightly worse ground power; or has a combination of relatively poor quality air power and poor quality ground power; your ground power alone could win the war.
And again, I say this because ground power alone has won wars. There is a long history of that.
Is that it? Mind you, I'm fully on board the possibility that no army alone no matter how excellent (or with poor air power in support) can win a war against enemy ground power with excellent air power supporting it. The math allows this.
And indeed, it seems like the Russians simply want to nullify Western air power with ground-based air defenses to make air power a non-factor for both sides; but actually get an edge over NATO by expending resources not on nullified air power but on superior artillery and targeting capabilities to make their ground factor superior.
Anyway, that's my simplified model of air power.