Plenty of frameworks free you from the details of DOM updates and state transitions, basically any with templating are equivalent here. React pushed more on co

Plenty of frameworks free you from the details of DOM updates and state transitions, basically any with templating are equivalent here. React pushed more on components acting as pure functions of state to DOM, but that style was not totally uncommon before React. Even in many old MVC frameworks, the best practices would lead to "stateless" views, and often controllers that act as pure functions for ease of testing. I would say popularizing those functional principles, even if React actually implements them somewhat loosely, is Reacts best contribution. Eventually I think those principles will make their way into Web Components implementations, and we'll have interoperable components with React-like internals interoperating with any other off-the-shelf web component.