I recently started using Sapper for a personal site and have been enjoying it immensely. I find that the abstractions that Sapper/Svelte make in order to avoid full page loads, preload data, etc allow me to write the site in a component-oriented way while not shipping 5MB of JS to the browser. And, Sapper scales as the app gets bigger in a way that a raw static site just can't.

Rich seems to be advocating for a JS middle-ground here, which I think is a great direction to go in for this kind of workflow.