However, if all of these are hosted in the same repository, you lose a lot of those benefits.

mixing the turing complete of javascript with the markup of HTML eliminates the readability of JSX so that it is actually harder to parse than a solution like hyperscript

The problem with working around the current limitations of Svelte style (:global, svelte:head, external styles or various wild card selectors) is that the API is uglier, bigger, harder to explain AND it loses one of the best features of Svelte IMO - contextual style encapsulation. I can understand that CSS classes are a bit uncontrollable, but this type of blocking will just push developers to work around it and create worse solutions.