React, a popular JavaScript library, can be used to build accessible web applications. While there are valid concerns about React's accessibility, it is not inherently inaccessible, and its state management and reactivity can be leveraged to provide context for all users. Key best practices include using semantic HTML structuring, grouping elements with Fragments, and managing focus using refs. Additionally, leveraging React's lifecycle events and event listeners can help toggle ARIA states and properties in response to changes in the virtual DOM. By mastering the fundamentals of web accessibility and utilizing React's features, developers can build accessible React apps that provide a good user experience for all users.