Leetcode is a great service, and my favorite one when it comes to solving algorithmic tasks.

Clojure, on the other hand, is the most paid and the third most loved language.
It has been growing steadily, check google trends for the last year (proof).

And Clojure is extremely concise. For example, here is how to transpose a matrix:

(defn transpose [m] 
  (apply map list m))

And here is a max subarray sum algorithm:

(defn max-sub-seq [sq]
  (apply max (reductions #(max (+ %1 %2) 0) 0 sq)))

Concise, but still performs well. And still there are lots of optimizations possible here.

So people will definitely have fun solving tasks in this language!