It’s good when you want interactivity that’s technically straightforward but in high volume.
It doesn’t work for code editors because they need very close interaction with the DOM, whereas React provides an abstraction layer that covers the common cases.
It works but clearly it's not needed, and to me I don't see a whole lot of innovation from a computer science standpoint because the most complex js projects don't use it.
1. Building apps with manual mutations (which is what we did before in the jQuery era). This involves a lot of boilerplate code, and it is hard to ensure that the UI state stays in sync with the app state properly.
2. Re-render the world on every state change. This works and allows you write simple code that is react-like in that it is pure transformation of app state into UI state, but it's slow and quickly runs into performance issues even in small apps.
1 still makes sense in the most performance sensitive scenarios. And 2 can work for the very simplest apps. But React and similar frameworks are great for everything in between.
> I don't see a whole lot of innovation from a computer science standpoint because the most complex js projects don't use it.
That seems silly. You could make the same argument for something like SQL. The most complex data manipulations won't use it. But it's still useful for the 90% that aren't that complex.
It doesn’t work for code editors because they need very close interaction with the DOM, whereas React provides an abstraction layer that covers the common cases.