What do you mean by "develop environment"? Are you referring to IDE support or features like mix, IEx, pry, releases, etc.?

If the latter, Elixir has one of the best development environments, in my opinion. Mix is fantastic, releases are easy, and Elixir's error messages in IEx are the clearest I've seen in my 30+ year career.

I use Emacs to write code, and beyond syntax coloring, I don't want anything else, so you may have a point if you're talking about IDE support.

as others have said, there’s a lot of work going into improving the dev experience.

There were 3 LSP implementations. they’re getting combined, so IDE support should improve.

There’s technically a step through debugger, but it’s extremely slow if you actually get it working.

There is a new type system too.

A bunch of work is currently going into improving that.