I've used react for internal administrative tools for configuring UI, and the ability to do a real-time preview of what the UI will look like based on how you'v

I've used react for internal administrative tools for configuring UI, and the ability to do a real-time preview of what the UI will look like based on how you've configured it is pretty useful. Also used it a number of times to build form inputs that aren't natively supported ("list of objects all with the same properties where you can select and make a change to a bunch at once" sort of thing). Basically I've found that if you're doing something useful which could be done with jquery but would probably have had subtle bugs due to a combinatorial explosion of possible states, you can usually use react in that context to make a cleaner, faster, and less buggy version of that same UI that is faster to develop and easier to reason about (and thus better for the end user, since software that works consistently is more valuable than software that mostly works as long as you don't breathe wrong near it). If you're looking for examples where a single-page app is better than server-side-rendered HTML with some javascript sprinkled in to make certain components more interactive, though, I can't help you. The successful use cases I've seen for react are of the "use it as the way you sprinkle additional functionality into your server-side-rendered HTML" type.