JS classes are one of the things I'm most unsure about in the direction of the language. On the one hand, it is nice to have a form of abstraction of prototypes that is quite close to the typical mode of programming used in popular languages like Python and Java. On the other hand, it is quite a needless abstraction for a well-functioning system. The ease with which a class system can be implemented on top of prototypes just shows how prototypes embody the JS spirit: Flexible, powerful, a bit too easy to shoot yourself in the foot with.