Yes, because you can't run C++ in the client, while some Node libraries can now use the same code for pre-rendering pages on the server or rendering new pages on the client. This gets you the best of both worlds, where a first load or refresh has the page content baked in like a traditional static site, but once it loads you get faster naetvigation and live content updates.

(WASM and WAPI might eventually let you run WASM-compiled C++ in the client, but there's still a lot up in the air for interop purposes there.)