Your first impression is the same as mine. Elixir/Phoenix is absolutely fantastic and could likely be the future of web design - as soon as everyone realize that all that Node stuff was a huge mistake. That being said, Elixir is a pretty new language and the user base isn't all that huge. Both being arguments against using Elixir in a real production environment. My point being that if you are looking at acquiring skills for future employment, Elixir may not be the best bet. In that case, Golang or Ruby even, would make more sense.