Erlang is a particularly low-friction language, in my experience; it’s just as productive (for me, at least) to edit Erlang code in vim (with no active extensions other than Erlang syntax-highlighting) as it is to edit it in Sublime Text with the whiz-bang Erlang Language Server compiling it in the background. Code that won’t compile just looks wrong in Erlang, and it’s not subtle.

Elixir is slightly higher-friction; all that weird extra Erlang syntax that Elixir eschews (the comma and semicolon statement-binding operators specifically) has a purpose in making Erlang “mentally lintable”, so Elixir loses some of that.

It gains in other places, though; for example, Elixir’s hygenic macros impose much less of a mental load than Erlang’s parse-transforms do. (Just the fact that you have to explicitly require the definition-site module before using any macro from that module, is a big boon to predicting what’ll happen when you go to run the code.)