The same reason frameworks are popular in any language: convention over configuration. In a native lang there is are near infinite choices to make in implement

The same reason frameworks are popular in any language: convention over configuration. In a native lang there is are near infinite choices to make in implementing a solution and no two developer’s native code typically looks the same. Jumping into a vanilla JS codebase can sometimes take more time because you have to discover and understand the choices the developer made. The code is highly configurable but lacks a common convention. With a framework, some of those choices have been made for you. So, jumping into a framework codebase is sometimes easier and simpler for those that understand the framework. The code adheres to a public convention at the expense of being less configurable.