It is using a Component; it's subtle but in the example "Drawing" is a Function Component that is declared using an arrow function. Hooks don't replace Components, but are a way to have state in what were previously known as Stateless Somponents (now Function Components), as well as encapsulating other React features. I personally prefer good old Pure Components.
Okay, I guess you could attach that functionality to an existing component.
It just feels wrong to me, that you would put something that looks like a separate component into a hook to inject into another component.
I thought there was some benefit in doing it like this, that I cannot think of...
The main goal of React hooks was the shrinking of the component tree. Most people would probably create their own version of an SVG component and then they would have to nest the library component. Now they just have to throw in the hook and be done with it.