In fact, React itself now makes use of render props in its own context API

It is used to expose internal data from within a render prop component for making it accessible to other components within the render prop component's composition.

However, again you would have to lift state up to the App component in order to pass the amount to the currency components. As you can see, the component composition on its own doesn't help us to solve the problem. That's the point where React's render props pattern comes into play which enhances React's component composition with an important ingredient: a render function.