React components explained without the hype - what CTOs need to know

The component model that won

React components - reusable JavaScript functions returning UI pieces - dominate enterprise frontend development for a reason. They work. APAC firms from Alibaba to local fintechs use them for dashboards that need to scale.

The architecture is straightforward: break UI into discrete chunks (headers, buttons, cards), manage them independently, compose as needed. It's not revolutionary - it's practical modular design applied to interfaces.

What changed in 2019

Functional components with hooks replaced class components in React 16.8. Most new code uses this pattern:

function Welcome() {
  return <h1>Hello, React!</h1>;
}

Versus the older class syntax that required more boilerplate. The functional approach won because it's simpler to reason about and test.

The migration reality

Here's what enterprise teams actually face: legacy codebases still running class components. The official recommendation is functional, but the transition cost is real. Teams report hitting the same issues:

• useEffect dependency arrays triggering infinite loops (object references change on every render)
• Cleanup functions not running as expected on unmount
• Closure-based memory leaks in long-running components

These aren't beginner mistakes - they're architectural patterns that behave differently than class lifecycle methods.

The numbers

React: 40M+ weekly npm downloads. Frontend framework share around 40% (State of JS 2024). The ecosystem is worth over $10 billion when counting libraries like Material UI.

That adoption creates lock-in effects worth considering. Switching costs are high when your entire team knows React and your component library is built on it.

What skeptics say

Fair criticism exists. Svelte compiles components away at build time - no runtime overhead. Vue uses templates instead of JSX - less JavaScript mixing with markup. Both claim simpler mental models.

React's counter: ecosystem maturity and hiring pool depth. Those matter for enterprise deployment timelines.

Worth noting

If you're evaluating React for new projects in 2025: the component model is stable, the hooks API is settled, and the migration path from classes is well-documented. The framework isn't going anywhere - Meta backs it, and the market has spoken.

The real question is whether your team can ship components that don't accumulate technical debt. The architecture enables that. Execution determines it.