RRv7 is great. It does the heavy lifting of what you'd use this kind of framework for in the first place (one codebase in one language - typescript - one "stack"/lib tree - that does both the server and the client rendering), handles routing, route modules, code splitting, bundling, etc. etc.
Having to know node (or other supported server) and needing to implement your server business logic from scratch (models, db access, caching layer with redis or something, etc. etc.) is not a weakness, it's a strength.
The thing that .net tried to do for like a decade and failed to (one stack for both the server and the client), see Blazor bullshit etc. is handled here. Imagine you need a modern web app or a shop or whatever and that means React. It just does. Your backend stack is PHP or Rails or Go or whatever. Now you have to somehow square the hydration circle which you can't do without it being a massive pita (as PHP renders a page on the backend in.. well.. PHP) so you end up passing the data manually in some blobs of jsons or whatever with each request (or even worse, side to it in some fetches) that then React initializes from on the client and it's a total mess. Not to mention that unless you render the page in both php and react (try to keep both outputs the same lmao), you'll only see the full app "on the client" meaning crawlers/bots/google have to run JS on all your pages or see nonsense ... yikes.
SSR with hydration is there for this reason. You render the same React tree both on the server and on the client. The hydration process itself is made much easier by RR and its infrastructure (automatic passing of data to the client). Hell, thanks to SSR you don't even have to have JS enabled on the client if you're using just basic web standarts (see RRv7 docs on progressive enhancement and state management) and the site will work. This means even crawlers without JS runtimes will be able to index your site.