Frontend frameworks are an essential tool for web development because they provide a structured and organized approach to building the user interface of a web application. They help developers create consistent and efficient layouts, styles, and interactions, making developing and maintaining a web application easier over time.
It allows your web apps to interact with APIs in the same way as any other program (on desktop OS, mobile device, or elsewhere). Moreover, front-end frameworks can improve the user experience as they keep the common parts of the page intact (like navigation, etc.) and load whatever data the user requests instead of flashing and reloading with every click.