Are React-like UI frameworks a fad or a genuine step forward?

I'm currently building a toy web application in Rust (end-to-end, using WASM on the frontend). When checking out the Rust frontend dev landscape, I found that basically all relevant libraries/frameworks are React-like:

- components that receive props and pass props to their children

- state updates triggered by async messages like in Redux

- some JSX-like syntax

Since I'm already familiar with React/Redux, this works out well for me. But I couldn't help but notice the monoculture. I suppose some of this is due to the unidirectional data flow model being a good match to Rust's ownership system.

My question is if this monoculture, as well as the general buzz around React (and similar frameworks like Vue or Svelte) is just a fad, or if we're all really taking a genuine step forward in understanding how best to structure GUI code.

From my POV, React is a genuine step forward compared to the jQuery-based apps from 10 years ago that were a hot mess of disjointed updates. But I'd like to hear some perspectives from others, esp. those of you who have worked with GUI frameworks on other platforms over the years. I have a few years of Qt under my belt, but I'm undecided on whether the differences between Qt and React/etc. are significant or just an artifact of the different programming paradigms encouraged by their respective languages.