Many functions and macros in Clojure rely on reducing variadic parameters using recursion, e.g. (defn max "Returns the greatest of the nums." ([x] x)

Many functions and macros in Clojure rely on reducing variadic parameters using recursion, e.g. (defn max "Returns the greatest of the nums." ([x] x) ([x y] (. clojure.lang.Numbers (max x y))) ([x y & more] (reduce1 max (max x y) more))) You'd be limited to 2 params if you didn't have variadicity. Some macros like switching, which in Clojure is called `condp`, would lose their elegant single-parens appearance if variadicity wasn't allowed.