“Throughout the history of warfare for every great thing there is a countermeasure - often surprisingly cheap.”
I wonder how the S-400 would do against the Wild Weasel.
Imagine a B2 bomber deploying an army of smart kamikaze drones over a battle space. They are rather stealthy - hard to see and hard to hit. Each of them only needs a small explosive charge to destroy SAM radar or launchers and they can glide for an extended amount of time...... I don’t think the traditional AA systems have much of a chance in the future.
We are already testing and likely deploying stingers on drones so the world is going to change in another way. The future of manned aviation - especially with the development of long range or space based directed energy weapons - will be much different.