This is a hard generalization to make, but it's certainly true in the worst network condition case. Even if your client-side rendering happens instantaneously and your JS is (magically) 1kB, it's still 2 round trips before you can render anything instead of 1 (well, 4 instead of 3 for TCP connect, SSL handshake, HTML response). On poor mobile connections, a roundtrip will be 500ms+, so if you can render in less time than that on the server, it'll feel faster.

Evaluate + Layout + Render is not likely to be faster than Layout + Render for equivalent content.

Maybe this? https://signalvnoise.com/posts/3112-how-basecamp-next-got-to...

The issue is not so much about whether React components themselves are rendered on the client or server, it's about the network: all the JS and other data that has to be loaded in general before the browser can begin rendering.

With React you can use the same component code used on the client side to generate HTML on the server side and send that down the wire for first page load. The browser doesn't have to sit there waiting for entire libraries to load and then start building <div>s.