Here's what you need for Java:
Download SDKMan/Jenv
Install the version(s) of Java you need for your projects
Make sure your JAVA_HOME environment variable is set
Ensure your IDEs locate the correct Java home
Compared to all that, Elixir's two installers are trivial.
And if you have a competent package manager, you can just tell it to get Elixir and it'll handle Erlang for free.
No you don't. The process is exactly the same for Java.