I always wanted to learn Elixir but never had a project where it could show it strengths. Good old PHP works perfectly fine.
Also corporations like their devs to be easily replaceable which is easier with more mainstream languages, so it is always hard for "newer" languages to gain traction. That said I am totally rooting for Elixir.
I know of a Haskell shop and everybody said they’d have a hell of a time finding people… but all them nerds were (and are) tripping over themselves to work there because they love Haskell… though some I’ve talked to ended up not liking Haskell in production after working there. There seems to be a similar dynamic, if a bit less extreme, in Elixir shops.
But even bog-standard business processes eventually find the need for data-processing, crypto and parsing - the use-cases where people code Elixir NIF's. That is why for example you have projects like html5ever_elixir for parsing HTML/XML. Another use case is crypto - you have NIF's for several crypto libraries. Data processing - there are NIF's for Rust polars.
From a technical perspective, this is the overwhelming majority of what makes the Net happen. BEAM is great for that and many other things, like extremely reliable communication streams.
Use the right tool for the job. Rust sucks for high-level systems automation but that doesn’t make it any less useful than bash. It’s all about about use cases and Elixir fits many common use cases nicely, while providing some nice-to-haves that people often ask for in other common web dev environments.
If you use type guards correctly the performance can be surprisingly good. Not C/C++/Rust/Go/Java good, but not too far off either. This is definitely a corner-case though.
The current tool to wrap your bytecode with a VM so that it becomes standalone is Burrito[1], but there's some language support[2] (I think only for the arch that your CPU is currently running? contra Golang) and an older project called Distillery[3].
1: https://github.com/burrito-elixir/burrito