Soviet AA isn't even the biggest threat - As many Ukrainian pilots put it, the main threat is the R-37M. You can at least fly low and out of the way to defend against SAMs, but without a missile like the Meteor there is no answer to the combination of long range SAMs and R-37M carrying fighters.

Basically the problem is that to avoid AA you have to fly low or far from the front lines. If you fly low, you can't give enough energy to your missile to threaten even just Russian bombers.

If you fly high but far away, there is no way to deal with Russian planes carrying R-37s that will be able to fire their missiles far before you.

The only way to even the playing field would be to give Ukraine modern Gripens with the Meteor missile, as the F-16 cannot fire the Meteor.