Clojure is such a fun language to write; it has great concurrency tools from the get go, and since it has access to the entire Java ecosystem you're never hurting for libraries.

I find myself missing Clojure-style multimethods in most languages that aren't Clojure (or Erlang); once multimethods clicked for me, it seemed so blatantly obvious to me that it's the "correct" way to do modular programming that I get a little annoyed at languages that don't support it. And core.async is simply wonderful. There are lots of great concurrency libraries in lots of languages that give you CSP-style semantics (e.g. Tokio in Rust) but none of them have felt quite as natural to me as core.async.

I haven't had a chance to touch Clojure in serious capacity in awhile, though I have been tempted to see if I can get Claude to generate decent bindings for Vert.x to port over a personal project I've been doing in Java.