Wastegates are vital in turbocharged engines for regulating boost pressure, preventing overboost, and enhancing engine efficiency. They act as pressure relief valves, controlling the turbocharger's speed and ensuring safe boost levels. By diverting exhaust gases, wastegates protect the turbocharger from damage and allow for precise tuning of the engine's performance. Overall, wastegates play a crucial role in optimizing turbocharger systems for power, reliability, and durability.