You underestimate the destructive potential of even small drones. Quantity has a quality all its own. Imagine a swarm of thousands of drones, all cheaply built 3D printed things, made by a single individual or small group. They have one task. They fly to a fixed set of GPS coordinates and land. No targeting needed. No AI facial recognition to target some specific politician. No auto-gun mounted beneath a large drone. Just a dirt simple task. They just fly up, over, and down. Once landed, they send a small electrical signal to a small incendiary device, perhaps a thermite charge, installed at the base of the drone. Such drones could be made quite cheaply if made on a large scale.

Imagine fires being started atop the roofs of every building in a city. Oh, and the attack starts with each fire station being attacked by a dozen such drones. Imagine every building in a city being lit on fire simultaneously. Soon a firestorm develops, and the fire starts feeding itself.

Let’s say you needed 10,000 such drones. Maybe you make them for $50 each. That’s $500k to burn down a city. For the cost of a single building you can burn down every other building in a modest sized city.

We are approaching a point where a single determined individual, using the scale of resources regularly available to a single individual, could recreate the firebombing of Dresden.