You're missing the point. You're talking about what you used for your project. I'm talking about learning skills so I can walk into an interview for a job that says "we need React developers". They may use any number of these things I mentioned, or are thinking about using them, and will bring them up. As a "React developer" I have to be aware of the ecosystem. So it's not just "learn an API with a few functions".

And, as I said, it matters not whether I learned these things on my own: to Get the Job you need to demonstrate real-world experience.