React is a popular and efficient tool for building websites and apps, offering a harmonious integration of JavaScript and HTML within the same files. It allows for the creation of reusable components that consistently render data, utilizing a virtual tree reconciliation method to minimize changes to the DOM and efficiently update data. React is flexible and can be incrementally integrated into existing projects, unlike other technologies that require complete control of the entire page. It supports a component-based architecture, advocating for the single responsibility principle, which facilitates collaboration with designers to maintain consistent naming conventions. Additionally, React can be used with Gatsby, which simplifies data integration, page creation, and routing, while enhancing performance through static file loading, making it an ideal choice for developing modern PWA frameworks.