US/West has always focussed more on aircraft to do the job, not huge SAM systems.

no matter how great a SAM system is, attacking aircraft hold the initiative of when to strike and when to pull back. sooner or later, a determined and smart attack will blow holes in a SAM based network esp with very accurate satellite imagery, GPS guided munitions and long sticks like JASSM.

Russia should invest into a JSFski asap if it wants to remain competitive.