https://testmysite.io/5a4c2cdf819876444fa127b5/hn.svelte.tec...
I really like Svelte! But I don't even serve my content from Express middleware anymore due to the above problem.
I just feel like you're under-estimating a developer's resourcefulness to make the content that actually is static a static page, and also over-estimating the number of new, traditional client/server web apps (at least by people who are probably in your target audience).
Static performance is hard to beat especially globally and there's a clear performance degradation once you get away from the epicenter. Believe it or not Svelte.technology's landing page actually performs noticeably more poorly coast to coast in the US (>2x worse to load in California than NY--150ms vs 500ms).
I'm not saying give up or anything, just saying it might be a good idea to talk to more JAMStack people :)