Would you say that Elixir implements some or all of Alan Kay's definition of object-oriented design?

I totally agree with you from the performance standpoint, however I want to introduce another point: software resilience in context of the development. Languages like c#, java, ruby offer those optimizations on behalf of development complexity.

While this is kind of a stupid argument from an engineering point of view, I could argue that nowadays the ability to write resilient software with minimal investments (developers and time) is as important if not more important than performance.