All in all it depends on your definition of “Object Oriented”
Alan Kay, the person who is credited with coined the term “Object Oriented Programming” described it as a programming model with lots of independent processing units that maintained their own data and could communicate with one another through message passing.
That is the very essence of the Erlang (and by extension, Elixir) programming model. The units, independent in memory and compute, are known as Processes and they can communicate using message passing. This aligns very closely with the model that Alan Kay described. (He has since lamented the term saying if he had to do so again he might call it “Message Oriented” - to increase the emphasis on the separation of the processing units).
“Object Oriented Languages” grew from this concept to describe a language which sets aside a small piece of memory, of “state”, and controls access to that memory through language constructs (Encapsulation). The paradigm grew to include concepts like Inheritance (or prototyping) to allow for code reuse. And Polymorphism to help a developer apply problems solved in the abstract to concrete solutions. The task of learning “Object Oriented Programming” then, is focused on learning and applying these concepts - understanding how to use Encapsulation, Inheritance, and Polymorphism to solve problems. While these are good concepts - they are not fundamental to the “pure” concept that Alan Kay described.
If your goal is to learn those concepts, and how to work with them effectively, so that you can use any “Object Oriented Language” (C++, C#, Java, JavaScript, Objective-C, Swift, etc.) then learning Elixir is probably not the best vehicle to study. In some sense this the “practical” definition of “Object Oriented” in the modern lexicon.
If you are looking for an environment that is much closer to the “pure” concept of “Object Oriented Programming” as described by the person that coined the term then the BEAM and associated languages, including Elixir, may be your best bet.
