Earlier quoted context omitted.
Think of the fpv drone like a smol guided TOW missile at extremely low cost. The artillery, while destructive, is not going to be nearly as accurate. If you want artillery to hit something on the move accurately you want something like a laser adjusted Excalibur round. The drone is actually extremely efficient.
Laser-guided artillery rounds have been around a while. The Soviets were using laser-guided 240mm heavy mortar rounds in Afghanistan. https://www.tandfonline.com/doi/abs/10.1080/1351804050035499... https://en.wikipedia.org/wiki/Krasnopol_(weapon_system) https://en.wikipedia.org/wiki/M712_Copperhead
Laser guided Excalibur rounds didn't come out until much later, same for the laser guided jdams. And the cost of those is much higher, plus logistical an deployment cost, than a FPV drone.
Edit: I also don't know anybody that ever fired a copperhead round in anger. That was very much a product of 80s and 90s doctrine to counter Russian armor.