It was here, and here. I wasn’t really proposing it, just explaining the concept. Although I do think isomorphic rendering is highly desirable, the point is moot if we’re not developing a SPA.
When you use isomorphic rendering, exactly the same code runs on the server, that runs in the browser. Usually you do this to render the first page load on the server, and then the client takes over from there, but for people who don’t have JS, they continue using server renders.
You said the following:
adding a fallback so that the site does work for them means basically writing exactly the same software as we would if it wasn’t an SPA in the first place. One way you lose users, the other way you’re doubling the work you have to do.
By using isomorphic rendering, you’re giving yourself a fallback, without doubling your work, because the same code runs on the server and the client.