Yes, I like your last line. If a language is well documented you can pick it up in no time if you know the timeless concepts of programming in general.
Like in rails if I want to add authentication, I drop in devise, and in 30 minutes I have a fully tested user auth system, complete with password locking and reset mechanics.
Yes I could write it myself, but I'd not typically do that. No amount of docs on the language get that kind of boost in productivity.
In elixir I could write a fully functional integration with Kafka, but Broadway already does that. The docs on the language don't get me knowledge of all the libraries out there. That's just Time in and good co-workers. (great ones really)