Since I am developing on a daily basis with React, it is obviously my favorite choice. It is not a framework, but a view layer library. However, by only using the view layer you can already build frontend applications.
The ecosystem around React is huge. But you don't have to use anything to build an application with React. [0] For instance, most people try too early to use a state management library. But you don't have to use it from the start [1], because React comes with its own internal state management. It makes sense to learn the React fundamentals first and build your own application with it [2] before you dive deeper into the ecosystem [3].