React Native slowdowns may stem from memory leaks, not re-render issues

Performance degradation in React Native apps is often misattributed to rendering inefficiencies, when the real cause may be memory leaks from unmounted screens. Event listeners, intervals, and subscriptions that lack proper cleanup continue running in the background after a user navigates away. Each revisit to an affected screen can stack additional active callbacks, leading to duplicate API calls, repeated state updates, and increased battery drain. The problem typically emerges gradually, making it harder to detect during short test sessions. Developers are advised to always return a cleanup function from useEffect to remove listeners and clear intervals when a component unmounts.