Author A argues that the pursuit of efficiency is indispensable for the development of modern society, while Author B points out the negative aspects of efficiency-first ideology and asserts the need to re-evaluate human values found in inefficiency. Both authors are examining the challenges of modern society from different perspectives (A focusing on productivity and sustainability, B on the potential loss of humanity). They are both presenting their respective solutions and values in response to the 'challenges facing modern society,' which is the commonality in their emphasis.