Is there a good solution to rendering something like a react app to a static page? I feel like there are a lot of pages that don't really need client-side html rendering, but they have it because react is a good solution for modular web content.
You could automate it with Selenium (headless Chrome). I think Googlebot does something similar?
I think what the OP was asking was more along the lines of partial hydration (where only parts of the DOM are hydrated by React/other framework) or no hydration (no JavaScript is loaded at all).
11ty does the latter: https://www.11ty.dev
The React team are working on partial hydration and announced it in December. Vercel did a write up on it here: https://vercel.com/blog/everything-about-react-server-compon...