Echo JS 0.11.0

React alone leaves quite a bit to be desired from medium applications and larger, though. One day maybe we'll feel the necessity of Redux or similar to be too much of a hassle.

If you don't have some form of state management, then you don't have an application... there are some abstractions that may work better than redux, such as the many graphql implementations that have been coming out.

That's the point: React doesn't have a state management layer. Which means you can choose the one that best suits your needs.
But also means that you need to make an additional effort to create a meaningful application. Will you use Redux or MobX? This freedom lessens the reusability potential of your components by a lot. What about the components you wrote just a year ago with Flux in mind?

But it's just one of the drawbacks of React. I won't list another, because the concept is: whatever looks cool now, will always have its flaws, and sooner or later something will come out that will make your current library look like crap.

Today we're all getting shivers when someone mentions "jQuery", but once it was the greatest thing since sliced bread.

There's no definitive JavaScript library. Libraries come and go. Only JavaScript remains.

If you're targeting reusable components, then state should be left to the user of your component, or isolated internally via whatever mechanism you like, depending on the component.

That said, some will look better or worse over time, and component libraries will vary.  I mean there's Bootstrap, Semantic UI, Material UI and many other UI component libraries.  How well a given one fits into the react space, or even your own application will vary.  That's the nature of programming.

That said, in 20+ years of developing web applications, React is the first (of very many) web frameworks that felt like the right way to do components.  I'm not expecting that it will not eventually be replaced, only that of what I've seen lately, nothing is better enough to replace its' usage... though one might consider another JSX based implementation that's compatible (preact-compat).  I also remember many the libraries that were popular before jQuery came about (Prototype, mootools, etc).