Why ReactDOM is separated from React?
The React team worked on extracting all DOM-related features into a separate library called ReactDOM. React v0.14 is the first release in which the libraries are split. By looking at some of the packages,
react-three, it has become clear that the beauty and essence of React has nothing to do with browsers or the DOM.
To build more environments that React can render to, React team planned to split the main React package into two:
react-dom. This paves the way to writing components that can be shared between the web version of React and React Native.