Why would you say that? The Red AF kicked the snot out of the Germans in time. In fact it was precisely because they became so effective in the end that the Red AF was able to dominate the battlefield from Kursk on. One additional note one of the most effective ground attack aircraft was the Sturmovik.
Excerpt from Wiki...the Germans WISHED they had this.
The Ilyushin Il-2 was a ground attack aircraft (Shturmovik) in the Second World War, produced by the Soviet Union in very large numbers. In combination with its successor, the Ilyushin Il-10, a total of 42,330 were built, making it the single most produced military aircraft design in all of aviation history, as well as one of the most produced piloted aircraft in history along with the Cessna 172 and the Polikarpov Po-2. It is regarded as the best ground attack aircraft of World War 2. It was a prominent aircraft for tank killing with its accuracy in dive bombing and its 37mm guns penetrating their thin back armor.
To Il-2 pilots, the aircraft was simply the diminutive "Ilyusha". To the soldiers on the ground, it was the "Hunchback," the "Flying Tank" or the "Flying Infantryman". Its postwar NATO reporting name was "Bark". The Il-2 aircraft played a crucial role on the Eastern Front, and in Soviet opinion it was the most decisive aircraft in the history of modern land warfare. Joseph Stalin paid the Il-2 a great tribute in his own inimitable manner: when a particular production factory fell behind on its deliveries, Stalin sent an angrily-worded cable to the factory manager, stating "They are as essential to the Red Army as air and bread." [6
Much of the Russian Air Force is too crude to fly at night.