Why did World War II become such an aircraft-dependent war?

Why did the Allies have an advantage in the skies?

(See explanation below for further details)

Explanation:

Why did World War II become such an aircraft-dependent war?

Due to the need of destroying enemy infrastructure without needing the direct presence of infantry, minimizing human losses.

Why did the Allies have an advantage in the skies?

Since the Allies had a bigger industrial capacity for manufacturing thousands of airplanes in short time and a well-developed logistics to move them to the battlefront and keep them operational.