Why do you think planes fly so high often 10 Km above the gound?

Planes fly at high altitudes, often around 10 kilometers (33,000 feet), primarily to take advantage of thinner air, which reduces drag and increases fuel efficiency. Additionally, flying at higher altitudes allows aircraft to avoid most weather disturbances and turbulence, providing a smoother ride. The reduced air pressure at these heights also enables jet engines to operate more efficiently. Lastly, higher altitudes enhance safety by providing more time for response in emergencies.