Elixir, or rather Phoenix - more specifically, is not good for traditional web apps, in my opinion. You will basically reinvent everything like in the JavaScript world. The functional way of programming looks great at first but there is a reason why it isn't used everywhere, if it is so good :). Feel free to explore though. And make your own opinion.
I've tried it a bit (via https://phoenixforrailsdevelopers.com/), and it seems very cool especially with the realtime features, but I greatly prefer Swift as a language.
The docs are bad, and when you google for answers you almost always find "here's how to do it rails" first.
All the things that Elixir sells as good fall under the YANGNI. Code swapping sounds great, until you add in docker and red green deploy.
Immutable data seems great, but threaded code isn't all that common in most web apps. (not near business logic threads that is)
I don't see it as mature enough (despite its history) And it's hard to hire for.