1. They make exceptionally few mistakes overall anyway;
2. Perhaps it is the interaction between armed force technology and their vehicles which creates problems for them (whether intentional or not from our side);
3. The majority of our land surface area is not inhabited at any given moment. Maybe these drones, or whatever they are, do not even care about life here, and are not particularly attracted to cities or people, and are statistically more likely to fail out of reach of most populated areas just because that's what our geographic distribution is like.
1. They make exceptionally few mistakes overall anyway;
2. Perhaps it is the interaction between armed force technology and their vehicles which creates problems for them (whether intentional or not from our side);
3. The majority of our land surface area is not inhabited at any given moment. Maybe these drones, or whatever they are, do not even care about life here, and are not particularly attracted to cities or people, and are statistically more likely to fail out of reach of most populated areas just because that's what our geographic distribution is like.