The All-or-Nothing Rendering Bottleneck Server-Side Rendering (SSR) is hailed as the ultimate solution for frontend SEO and performance, but traditional SSR harbors a massive, hidden architectural bottleneck. In standard Next.js Page Router architecture (or traditional monolithic frameworks), SSR operates on an "All-or-Nothing" paradigm. Imagine an enterprise analytics dashboard. The header, navigation bar, and user profile take 50 milliseconds to fetch from the database. However, the comp...