well, I think I can answer that question of yours since I agree with what previous orator has stated.
I personally don't know Go nor Scala, but I know Erlang and a bit of Haskell. Well, everything you can do in Erlang you can also do in perl, but! But some things will be easier to do in erlang, for example, to spawn a pool of thousands of processes for almost every client.
If you need an example of the radically new feature -- how about the well-known statement that 'if it compiles, it works'? This became possible because of strict typing plus pure functional approach in haskell. And in perl we still teaching newcomers to append those silly 'use strict; use warnings' lines in every single script.
I personally feel the lack of pure functions in perl. I like the idea of *guaranteed* absense of side-effects when it is not otherwise stated. I like to spawn a lot of isolated workers as simple as a *click* by two fingers. And no worries about threads and shared data and all that scary stuff -- we have actors communicating with each other by sending messages to each other. 'Everything is a process' can be a motto for erlang.
But despite of all that said above there's still a niche for perl. When I want, for example, to analyze the web server's output, or gather some data from logfile or even do some sketch on 'how it should work' using FCGI + nginx -- I don't know the better tool than perl for these kind of task.
Well, soething like that.