Now it’s war: Gen Z has finally snapped over climate change and financial inequality. In a viral audio clip on TikTok, a white-haired man in a baseball cap and polo shirt declares, “The millennials and Generation Z have the Peter Pan syndrome, they don’t ever want to grow up.” Thousands of teens have responded through remixed reaction videos and art projects with a simple phrase: “ok boomer.” “Ok boomer” has become Generation Z’s endlessly repeated retort to the problem of older people who just don’t get it, a rallying cry for millions of fed up kids. Teenagers use it to...