@babel/plugin-transform-async-generator-functions enables Babel to transform asynchronous generator functions. This allows older JavaScript engines, without native support for async generators, to run code using this modern feature. It converts async function* syntax into equivalent ES5 code using regenerator runtime. This ensures compatibility across different environments, allowing developers to use the latest JavaScript syntax while targeting older browsers and Node.js versions. Improves code maintainability by leveraging modern features.