I mean… if you want a perpetual drain on your enemies’ resources, you send harmless (unarmed, for the sake of international law) yet pervasive and unstoppable threats into the airspace, forcing them to either expend munitions shooting them down or ignore them and 1. lose security 2. increase noise to hide actual incursions.

It’s a good tactic and fairly cheap. Not sure why it hasn’t been used yet.