The ecosystem largely settled out in 2014 when everybody was "javascript fatigue" complaining. The developments since have mostly been refinements on details of the development setup or state management. There's new stuff but I'm pretty sure anybody who wrote React at the time would be comfortable with the slight modifications in the patterns of how things fit together.

We're kind of into the next generation of frameworks (Solid, Svelte 3, Vue 3) and that's more about how much JS is getting delivered to the client. The current area of exploration is "partial hydration" where the goal is to write stuff using the component model but do server rendering and only send JS for the parts of the page that'll change client side. For quite a few classes of application this would substantially reduce the size of JS over the wire. All this is less of a benefit than the state control React brought so I expect slower/partial adoption.

More broadly, there's been a resurgence of the render everything on the server and send html diffs approach in the form of alpine and htmx. The other potential area for change on the horizon is web assembly getting host bindings support so it doesn't have to bridge through JS to affect the DOM and other browser APIs.