[Weekender] AI made work faster. So why are workers more exhausted?

South Korea leads global workplace AI adoption, with 51.1% of workers using AI tools daily, according to a report by the Korea Institute for International Economic Policy. Despite AI’s promise of efficiency, many workers—like Kim, a data engineer at a major Korean search platform—report heightened fatigue as AI speeds up workflows without reducing overall demands. Tasks once handled by teams in weeks are now completed by individuals in half a day using AI coding tools, but this shift has eliminated easier work while multiplying complex responsibilities like reviewing AI output, coordinating across departments, and validating results. The pressure extends beyond South Korea, with 81% of managers in the US and UK reporting AI-driven productivity expectations, while 71% of employees experience burnout. Workers now juggle multiple AI systems for research, document summarization, and data analysis, leading to cognitive overload described as 'AI brain fry' by the Boston Consulting Group. This phenomenon causes chronic headaches, reduced concentration, and slower decision-making, particularly when using four or more AI tools simultaneously. Hyun Myung-ho, a psychology professor at Chung-Ang University, explains the strain stems from constant context-switching between AI prompts, reviews, and corrections, creating mental strain. Lee, a marketing analyst in Seoul, notes executives often assume AI-generated reports require minimal human input, only to discover editing demands have doubled. Jeon, a content creator, echoes this, describing how AI-generated content still demands extensive human refinement. Research shows productivity peaks with one or two AI tools but declines sharply when workers manage four or more systems. The shift has also introduced 'invisible labor,' where employees spend hours correcting AI outputs that supervisors assume are nearly complete. Workers report feeling overwhelmed by the blend of AI acceleration and unrelenting expectations, undermining the original promise of workplace liberation.