The big thing that FPV drones have going for them is that they're ludicrously cheap and easily constructed from relatively basic parts by moderately skilled people.
It's literally cheaper to strap a grenade to an FPV drone and fly it into a tank hatch than it is to fire a single non-precision artillery round, let alone tens or hundreds of them.
Plus, you can deploy your drones remotely from the top of a trunk deep behind enemy lines and fly them into irreplaceable strategic aviation assets with a shot exchange factor better than 1000x.
It's literally cheaper to strap a grenade to an FPV drone and fly it into a tank hatch than it is to fire a single non-precision artillery round, let alone tens or hundreds of them.
Plus, you can deploy your drones remotely from the top of a trunk deep behind enemy lines and fly them into irreplaceable strategic aviation assets with a shot exchange factor better than 1000x.