React is winning because its really good. Even if the cost is an extra few milliseconds of render time and few extra hours of dev time figuring out things like hook dependencies.
If React starts taking a backseat, it'll be because its no longer really good. And, to be fair: I've started to see this happen. Next & Vercel have totally taken over the React world, and they've proven to make quite poor architectural decisions. All great empires are destroyed from the inside, not out, and I think its possible Vercel could do this to React. But, also, even as Next seppukus itself, people will likely just fall back to React on Vite (or, there's Remix 3 that's I think still under development, but might end up being big).
If React starts taking a backseat, it'll be because its no longer really good. And, to be fair: I've started to see this happen. Next & Vercel have totally taken over the React world, and they've proven to make quite poor architectural decisions. All great empires are destroyed from the inside, not out, and I think its possible Vercel could do this to React. But, also, even as Next seppukus itself, people will likely just fall back to React on Vite (or, there's Remix 3 that's I think still under development, but might end up being big).