Elixir excels for building highly available networked backend applications. Not that it can’t be good for other things, but I personally tried my hand at it as a scripting language (as a complete newcomer to programming might). For this purpose I had to learn things like Erlang interop, module composition, setting up a mix project, etc. — just to get a small project off the ground. Even as a seasoned developer familiar with syntactically and conceptually comparable languages (Ruby, OCaml…) I found the self-instructional overhead to be atypically high for a programming environment.
This is a bit of a tangent, but I’ve noticed that whenever “best first language” discussions come up, responses tend to be biased toward whichever language people first scrapped something together in for fun. For me that was TI-BASIC. By no means do I think that was a “good” first language - it’s just what was around. But it passed the litmus test of letting me quickly iterate from writing calculator-crashing output loops to making little games for my friends.
For its virtues, Elixir was originally developed to serve a community of experienced web devs trying to solve problems most newcomers don’t know about and won’t encounter — and it shows. I think most novices would be better served by a more “mainstream” scripting language like Python, Ruby, JS, etc.