Coming from a Java background, it seems to me that a lot of what is going on in the JS world is similar to what enterprise software went through over the past 2

Coming from a Java background, it seems to me that a lot of what is going on in the JS world is similar to what enterprise software went through over the past 20 years: the "framework" craze. This is appropriate because websites and web apps are more complicated than ever before, and face the same challenges that traditional enterprise software faces: large codebases that stay around for a long time and need to be maintained and refactored, integration with various APIs, asynchronous communication, separation of concerns, separation of model and view, business logic, test coverage, development of different parts of the application by different parts of the engineering team, etc. At some point, the benefits a framework provides outweigh the time it takes to adopt and learn the framework. A framework provides an overall way of doing things that gives structure to the project and makes a lot of the challenges I mentioned easier to deal with. Frameworks significantly reduce the number of "how do I implement this feature?" questions that are bound to arise, by providing a standardized way of doing things. They make it easier for teams to collaborate, because the codebase is relatively consistent and engineers aren't constantly dealing with other team members' idiosyncratic code. (Yes, that means there is less room for individual creativity and expression, and it makes programmers interchangeable to some extent. Welcome to the world of business.) So, why are there so many more JavaScript frameworks than Java frameworks? I suspect it has to do with the low barrier to entry of programming in JavaScript as compared to Java. I also think that dissatisfaction with whatever frameworks are current is a major driver behind the creation of new frameworks. (I suspect that a lot of the dissatisfaction with the current frameworks is misdirected and is really due to the nature of JavaScript as a language, and TypeScript is an example of an explicit reaction to that). Another reason for the proliferation of frameworks is that the playing field keeps changing. Most recently, it has been smartphones and social media that have revolutionized the way people use the web. Before that, it was streaming video and "Web 2.0." Whatever the next big thing is, I'm sure it will inspire a new flurry of new web development frameworks.