There's a whole ecosystem around using React for static site development now, this is exactly what Gatsby is if I'm not mistaken. Use React as a more powerful templating system for authoring content, but generate most of it out as static HTML/CSS, while still having the capability for individual components to have interactivity / data fetching post load.

Also, I think this is what's going on with NextJS and React's server-side-components stuff. Having solved client-side webapps, the world has now turned to reinventing Cold Fusion...