Rendering to static HTML is actually pretty common. Admittedly, hydrating subtrees is fairly uncommon (at least where the full tree is also rendered by React server-side), but it’s well within the “happy path” and both patterns have been heavily promoted by React from very early on.

What’s not within the “happy path” is automating any sort of partial hydration process, which is unfortunate, but it seems pretty likely RSC is going to subsume that use case for most anyone trying to solve it with React.