It’s always mildly amusing how many engineers believe that React is a framework. I personally attribute it to lack of experience—once you’ve used enough proper frameworks, you’d laugh at that comparison. The fact that React is and always has been literally defined as a library right on its website doesn’t seem to stop them. Incidentally, many of the issues people have with React are attributable to this mistake: know…
On the first page "Quickstart" all code blocks contain code that contain JSX and call you. They do not even show the part where you need to call render. Copying this code into your codebase will not do anything.
On that same page they also introduce state management with hooks.
On the installation page npm installing react is not mentioned. They suggest using create react app.
Sure you can theoratically use react as a library but I've never seen it and from the website it seems like usage as a library is not the inteded way to use react.
The first sentence "The library for web and native user interfaces" is the only thing pointing to react being able to be used as a library. The rest of it looks like a framework to me.