... which is air defense.
This is to remind you that drone warfare evolves and I posted numbers before--despite some dramatic videos, the actual success rate of 404 UAVs is about 4%. It declined since. Drone against drone is now a normal occurrence and Russia is the first and so far the only country which introduced a new service--Troops of the Unmanned Systems--and established military 5 year academy specifically for educating officer corps for this type of the warfare. Obviously, Russian Navy will have a say on that, because they will argue (justifiably) that surface and underwater drones are a whole other thing altogether. They are.
Meanwhile, artillery and air force remain the most productive means of fire delivery.
And same applies to tanks.