[ricardobeat]

> 80% of the gain they got was just going from client-only to server-rendered

That's what the article is about, isn't it? The gain comes from going from client-only to server-rendered. They did this using RSC. You could also do it using handlebars and jQuery if it was 2010 (with probably 100x better performance).

> if you had compared SSR vs RSC you'd see that the numbers don't actually improve so much

From the article: We saw a whopping 62% reduction in bundle size as well as as 63% improvement in Google's Speed Index. You would not get those gains by simply enabling SSR in an existing app, as the bundle size will remain the same. Unless.. you use Astro or RSC to enable SSR with partial hydration. Which is what they did.

[nwienert]

No, speed index would go up massively. A huge amount of lighthouse improves with server rendered content.

Likewise RSC is not nearly as free as other partial hydration methods. You send a full serialized copy of the tree and props over that has to be manually de serialized. This nullifies much of the benefit. Further, you still send the large (even larger now) copy of React. This is exactly why the comparison would be interesting to see, and why I brought up my concerns - it seems people are pretty under informed about this.