Doesn't the Russian doctrine basically assume that they would lose head to head in air combat and sit behind a ton of layered S300 and S400 air defense systems? If they can't win, they can at least try to deny use of the airspace, and the loss of air support would make NATO combined arms tactics much less effective.
Not necessarily saying it's a winning strategy, but they are at least self-aware enough to adapt their tactics according to the reality of combat craft strength.

