the psychological effect is not be underestimated. while the war in Ukraine has shown how the omnipresence of drones has a strong psychological effect, you can try to fend them off and evade them or isolate yourself from them. well with people, anyone around you possibly being suicide bomber and no real means of protection from them, i would guess the terror they cause is quite a bit more pervasive
It’s basically the same terror that someone like Alvin York or The Harlem Hellfighters invoked via so few people causing so much damage. Both terrors are probably because to take such actions the person has to have no fear of death.