fleck is "Clojure-like" and is bash without some of the important semantics of Clojure. Babashka is using "Small Clojure Interpreter" (https://github.com/borkdude/sci) which is trying it's best to be as much like Clojure as possible. Might not be a good idea to use something that can't make the same claim, if your point is to learn Clojure.

I realize now that fleck (https://github.com/chr15m/flk) also doesn't even do destructuring and more. Finally the README in the bottom has "You might also be thinking of babashka which is a bare-metal solution using real Clojure".

Babashka is also not slow but rather fast (in startup time).