I see how a class can be extended, but I worry about highlighting this without caveating that even the React docs warn against extension in favor of composition and inversion control.

As it reads now, I can definitely imagine a newbie OOP programmer exclaiming, “ooo, that must be the way to make React *really* shine” and get into a world of trouble.

The main reason I can see for using classes in React is strictly for error boundaries, which can only be created using classes. Otherwise, React is really more aligned with FP fundamentals versus OOP.