In practice Russia uses Pantsir https://odin.t2com.army.mil/WEG/Asset/96K6_Pantsir-S1_(SA-22_Greyhound)_Russian_Short-Range_Air_Defense_Gun::Missile_System which has point defences rather than just using missiles. Russia has also developed Yolka https://en.wikipedia.org/wiki/Yolka_(drone_interceptor) interceptor drones. Also, cost of production in Russia is far lower than it is in the west. What you're reading in your link is projection, their analysis is based on what's happening to yanks in the war on Iran. Anybody who thinks Russia uses S300/400 or Buk systems to intercept drones is not engaging with reality.