SSR is different and does not provide the same performance of RSCs. With SSR you get the advantage of an initially rendered page, but you don’t have access to data or state. So you are just rendering placeholders until it hydrates and the client can request the data.

RSCs allow you to render the initial page with the content loaded right away.

That said, I am not sure about Tanstack’s implementation. Need to spend more time reading about this.

Here’s a nice post explaining why RSCs do what SSR cannot: https://www.joshwcomeau.com/react/server-components/