It can reduce the work required to fetch data and generate content in the browser. An SSR page can still contain client-only regions, so the label alone does not prove that all content and metadata are present.
Performance depends on server work, data access, caching, images and client scripts. Slow responses or heavy hydration can delay display and interaction. Measure relevant metrics such as TTFB, LCP and INP.
Choose request rendering, static generation and cache revalidation according to freshness, personalization and safe sharing requirements. Frequently changing pages may still use caching, and not every request must query a database.