Why React doesn’t update state immediately

React's asynchronous state updates, which are managed through batching, allow for multiple state changes without unnecessary re-renders, thus optimizing application performance. When you invoke state updates using setState or useState hooks, React queues these updates to be processed together, preventing immediate re-renders and ensuring efficient updates. This batching process can be crucial for performance, especially in larger applications, where multiple updates might otherwise cause performance issues. Techniques such as using key props for resetting child component states or managing dependencies in useEffect are essential for maintaining synchronization between parent and child components. Understanding and leveraging these mechanisms, like not directly mutating state objects, helps developers avoid unexpected behaviors and maintain optimal performance. Additionally, using callbacks in setState or leveraging the useEffect hook can aid in performing operations after state changes, enhancing the reactivity and user experience of React applications.