Not to take away from your core point, but I wouldn't say the human sensory system is mediocre. Your eyes are sensitive enough to see a candle flame at 2.6 km

Not to take away from your core point, but I wouldn't say the human sensory system is mediocre. Your eyes are sensitive enough to see a candle flame at 2.6 km away. A rod can actually be stimulated by a single photon, but the brain squelches activation that small. The human ear is sensitive enough to hear a watch tick from about 20 feet away in a quiet room. That's pretty darn good.