Everyone talks about GenServers and OTP and all that, and that part is great, but what sells it for me is that it's a practical functional programming language. You get 80% of the FP part of Haskell but you don't have to mess with monads. It has tail call optimization which makes it easy to write functions in general, one "function" is made up of several that call each other, much easier to reason about and write. In general code I use what I call the "holy trinity", atoms, tuples and pattern matching.

As for it being fun and addictive, I'm retired. I can write code in any language I want, or don't write at all, and I choose to write in Elixir.