I agree that air supremacy isn’t adequate by itself to win wars. However, it never was. The idea that you can blow up some enemy tanks and buildings and go home just like that was pie in the sky thinking from the beginning. I think the impression came from the Gulf War, where air power made Saddam’s military unable to function on the ground. However the circumstances were unique.
The premise that air superiority is somehow less important than before is absurd, however. Just because one element of war fighting alone isn’t all that is needed, it doesn’t follow that that element is not useful as a part of the multifaceted strategy. The idea that airpower alone (at least in the non-nuclear sense) can win most wars without boots on the ground is ridiculous. However the idea that letting the other guy control the skies is a viable policy is equally, or perhaps even more absurd.