I personally don’t have a great answer for you because I haven’t used the other languages much or at all. If you’re able to watch someone really effective at repl driven development, I think you’re able to see how that sets productivity in the language apart.
Bruce Hauman has given a few good talks about how you can use tools like Figwheel to bring a REPL-like development experience to web development.
You can watch him live-code the game 2048 in the screencast where he introduces DevCards[0]. Notice that the video came out 4 years ago!
One thing that really drew me to Clojure is that it seems to be a nexus of really good ideas that have trickled out into the larger community. If Clojure was where all the smart kids ate their lunch, maybe if I ate lunch with them too (so to speak), some of their smarts might rub off on me :)
