It would be a story about a civilization so technologically successful that it had quietly removed many of the reasons people once needed to belong.… When people spoke about social withdrawal in the late 2020s, they often spoke as though it were a disease of the mind. Psychologists discussed anxiety disorders. Journalists described loneliness. Politicians debated motivation, resilience, and personal responsibility. Dr. Ren Fujimoto, however, suspected that something larger was happening. He worked at a policy laboratory affiliated with a university in Tokyo, where researchers analyzed long-term demographic and labor trends. Unlike many clinicians, Fujimoto spent as much time studying housing costs, digital infrastructure, welfare systems, and artificial intelligence as he did reading psychology journals. His controversial argument was simple: “The question is not why some people choose to disconnect from society.” “The question is why society still assumes c...