AI copilots deliver measurable productivity gains (55% faster coding, 41% faster customer service resolution, 70% content cost reduction) but create a hidden cost: skill decay. Research shows AI assistance may accelerate expertise atrophy in both experts and learners, often without users noticing. The post examines where AI copilots genuinely deliver ROI, how to build risk-tiered governance frameworks without stifling innovation, how to measure deskilling, and what effective reskilling programmes look like. Key recommendations include alternating AI-assisted and manual work (drawing on aviation research), prioritizing explainability, continuous capability assessment, and integrating reskilling into daily workflows rather than treating it as one-time training.