"Efficiency" is such a dumb thing to optimize for singlemindedly. Overly efficient systems are brittle and can't adapt to shocks. Look what happened to the efficient global supply chain when that ship blocked the Suez Canal.

Imagine if we demanded "efficiency" from fire departments; they'd only hire as many firefighters as they need to respond to the average number of emergencies per day, then totally flop when there's a mass casualty event.