I wonder if the way to delete drones will be other drones.
Saw a demo of some drone flying, the camera was in the nose and you basically flew these sporty little micro drones about using the forward camera view on VR headsets - they were slaloming under the wings of parked planes on an airbase and "strafing" them by camera.
So micro-fighter squadrons to patrol the airspace, and likely fly as kamikazes to hit-to-kill? If thse fighter drones carried a warhead worth say 1 or 2 40mm grenades then they could also do ground attack on targets of reasonable value if the need arose.
Might not need an HE load if crash to kill is the modus operandi - just beef up the leading edge and nose in light steel rather than pathetic plastic, and be in effect a guided boomerang (might even survive the impact and make a second pass on another even if it was a wee bit bit wobbly after giving the first contact its "Glasgow Kiss" (i.e. a head butt!)
).