These things take time. Do you expect such a new language to be adopted by 90% of developers?
Elixir 1.0 was released 9 years ago. Most people use C, Python, Java which have been around for 30+ years. I use Elixir full time but I know I'm on the bleeding edge compared to the vast majority of developers, let alone corporations which operate and change over longer timescales, and Elixir is a major paradigm shift compared to pretty much any other language. A C shop might plan to move to Rust, but Elixir is a completely another universe.
A much more interesting question is why didn't Erlang get much of a foothold in the industry. The fact that you are asking this question today means that Elixir has been instrumental in putting Erlang/OTP in the conversation, so its usage might finally start to grow thanks to a simpler syntax, healthier ecosystem and, most importantly, a lot of commercial interest.
Elixir 1.0 was released 9 years ago. Most people use C, Python, Java which have been around for 30+ years. I use Elixir full time but I know I'm on the bleeding edge compared to the vast majority of developers, let alone corporations which operate and change over longer timescales, and Elixir is a major paradigm shift compared to pretty much any other language. A C shop might plan to move to Rust, but Elixir is a completely another universe.
A much more interesting question is why didn't Erlang get much of a foothold in the industry. The fact that you are asking this question today means that Elixir has been instrumental in putting Erlang/OTP in the conversation, so its usage might finally start to grow thanks to a simpler syntax, healthier ecosystem and, most importantly, a lot of commercial interest.