See but the parent comment is about "web applications" not "web pages". You are describing a web page - there is limited or no interactivity, what is there can be reasonably handled by forms. No one doubts that React isn't the tool for this area
Take a look at the hey email client. It's built by basecamp--the guys who created rails.
As for web app vs web page--it's a very blurry line, and it's rare that I end up building something where the entire site could be considered a web app. Usually only some small pieces of it demand enough interactivity to bother with the complexities of using a UI framework, and for that I wrap a small React or a Svelte app in a div and throw it on a page within the larger site.
