tl;dr: Tim Ferriss shares BookScan data showing his catalog of bestselling self-help books (4-Hour Workweek, etc.) declined 5% in 2023, 13% in 2024, 46% in 2025, and is tracking -57% in 2026—closely correlating with the rise of ChatGPT and LLMs. He argues prescriptive nonfiction is the canary in the coal mine, since "how-to" content is essentially a lookup table that chatbots now deliver faster, cheaper, and personalized for free—threatening YouTube tutorials, podcasts, courses, and journalism next. His bet: information businesses collapse into chatbots, while transformation, storytelling, voice, and personality remain the only durable moats.