The advantage for me is that it uses JSX. I like everything about Svelte except the weird semi-custom language, module format, and magical state management. Being able to produce similar (though probably still less optimized) products with plain JS functions which simply return a data structure, and which can easily render to other targets besides the browser, is fantastic.

Not except this is in React. So similar thing. Also Sapper as of recently is no longer a thing :).

Is Svelte compile-time? I don't think RSC are compile time, just server-time.