People who ask this question are implicitly asking:
"Given the difficulty/time requirements of learning something and the salary/technology trends of our industry, does it make sense to invest in the mastery of abstraction X?"
The time I have outside of my sprint is really limited, so getting expert guidance on whether knowing Rust will benefit me more than knowing Java is in fact extremely valuable to me.
That's a good point - it is highly dependent on what languages you already know from beforehand. If you know JavaScript already then it makes sense to learn a language that is not garbage collected, has no mutations or is not managed.
I would pick up Rust or Clojure before Java in this regard for example - though learning new languages gets way easier the more you learn.
"Given the difficulty/time requirements of learning something and the salary/technology trends of our industry, does it make sense to invest in the mastery of abstraction X?"
The time I have outside of my sprint is really limited, so getting expert guidance on whether knowing Rust will benefit me more than knowing Java is in fact extremely valuable to me.