Performance optimization in React apps is crucial because it directly impacts user experience. React apps, if not properly optimized, can suffer from slow renders, laggy interactions, and a heavy load on device resources — especially in large or dynamic applications.
When a React component re-renders unnecessarily, it consumes CPU and memory, leading to slow page loads, sluggish UI updates, and degraded performance on low-end devices. In severe cases, users might abandon slow apps altogether.

By optimizing React apps:

• We reduce the number of unnecessary re-renders.
• We improve initial load time and responsiveness.
• We ensure smoother user experiences, even in complex applications.
• We decrease energy and data consumption on mobile devices.

Optimization also becomes critical for SEO in server-side rendered React applications (like with Next.js), where faster Time-to-First-Byte (TTFB) and Time-to-Interactive (TTI) can greatly improve rankings.

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