Good point and I agree that the borders between SPA and SSR are blurry. However, I just wanted to stress that a debate without having requirements is useless, it's like saying a racing car is better than a truck. But for what? Building websites is not like building websites 20 years ago. There are many uses cases and saying one is better than the other rather shows that you never experienced the other side. I mean, there are still people out who never touched react, how should they fully grok what mighty system and ecosystem react has created and choosing another stack comes with much smaller or dying ecosystems.
To your points, I still think a proper SPA without any quirks such as DHTML, React Suspense, etc. gives the best UI for dashboard and logged-in kind of uses cases. However, having mixed environments is from a production and dev perspective subpar and hence you end up with setups like Next (SSR) with some Next pages having a stronger SPA notion (SPA within SSR).
To your points, I still think a proper SPA without any quirks such as DHTML, React Suspense, etc. gives the best UI for dashboard and logged-in kind of uses cases. However, having mixed environments is from a production and dev perspective subpar and hence you end up with setups like Next (SSR) with some Next pages having a stronger SPA notion (SPA within SSR).