Actually Next.js with App router (and with Pages being pushed out) is really bad for SPAs. See this thread: https://github.com/vercel/next.js/discussions/64660

> I think we will only be using Next.js for static sites/prebuilt SPA in the future.

With whats mentioned in the blog post I would not use it even from static builds.

You probably have better alternatives for that: Astro, React Router 7, TanStack.