A hyper-efficient system is inherently fragile: if something happens to any part of it, it has a big ripple effect all over the place, because there's no slack

A hyper-efficient system is inherently fragile: if something happens to any part of it, it has a big ripple effect all over the place, because there's no slack anywhere. More resilient systems always have some redundancy that helps them cope in a case of failure. If you think about societally optimal setup, it likely should include a mix of systems, from very efficient to very resilient. Something about eggs and baskets.