You're probably right with respect to manned aircraft. But line of sight lasers are bound by terrain. Swarms of very low flying, very small drones would defeat

You're probably right with respect to manned aircraft. But line of sight lasers are bound by terrain. Swarms of very low flying, very small drones would defeat such a system. Or drones inserted directly inside the country via spaceplane, avoiding the border lasers. This kind of thing isn't limited to aircraft. Once ground vehicles/drones have an automated turret that will immediately return fire, (or fire first depending on the kind of war) humans in front line combat might not work so well.