vite-plugin-ssr can't even be integrated with Vue Router (I saw you're working on deep integration though). They're both very rigid, early stage endeavours. [2] What happens, for ex, if you used nested lazy components in those pages, are they going to be included in the server render as well?
I mean, fair enough that there are people trying to do better, but it's extremely hard to find the right abstractions for such complex builds and Webpack is definitely on top here.
[1] https://github.com/sveltejs/kit/blob/5c2665ff2280947a2fc6001...
[2] https://github.com/brillout/vite-plugin-ssr/blob/master/src/...