Earlier quoted context omitted.
If you static render, it won't be an interactive application. With React SSR you get the best of both: stream static HTML chunks immediately, and rehydrate with JS later, prioritizing components the user interacts with. It should load quicker compared to traditional React apps where the browser loads the HTML, then loads the JS bundle, and only then renders a loading skeleton while likely triggering more requests for…
You seem to be confused about your terms, both SSR and SSG can rehydrate and become interactive, you only need SSR if you have personalized content that must be fetched on an actual user request, and with frameworks like astro introducing island concept it even let's you mix SSG and SSR content on a single page.
I did not interpret that as React SSG. SSG is the default behavior of NextJS unless you dynamically fetch data, turning it into SSR automatically.
What I thought of is React's "renderToString()" at build time which will produce static HTML with event handlers stripped, in preparation for a later "hydrateRoot()" on the client side.