I have a harsher take, 95% where react is used it is used without the need.
You want a good example of how a non-react website and its code might be structured, look at GitHub. At least from a user perspective, I've never had a problem using the back button or ctrl-clicking links while navigating GitHub - which is not something I can say of most other React and heavy-js websites.
That's.. basically every lib. Welcome to abstractions.