Maybe compared to duck typing inheritance increases cohesion. But classes in practice most often discourage cohesion. That's why they came up with Aspect-oriented programming. Not that that is practical, but it comes from the insight that organisation as stateful objects naturally leads to coupling, since you must lump most functionality into one mostly closed concept. And the odds are your next class will have a very similar structure regarding dependencies and implementation. And then you end up with inheritance just to share code, and end up with these totally meaningless ball-of-mud inheritance structures.

> Low level implementations that need efficient implementations of function calls

I'm pretty sure the most efficient "implementation" of function calls are still function calls.