> I could have gotten the same benefits with SSR and ported it to react native

Are you saying that rhetorically? In my experience, React is no silver bullet (e.g. different router and styling mechanisms for RN), trickiness dealing w/ timezones in SSR, etc.

And besides, the point here was largely about bundle size and fast time-to-interactive. Next.js optimizes a lot for developer experience, but you're definitely still going to be shipping a pretty sizeable JS bundle with slower characteristics than a hand-coded "closer-to-the-metal" thing.