Many macros can be translated to Haskell due to laziness. It's true that these can be difficult to translate or end up requiring TH. That's a downside, but it's rare.

And variadic functions are easily translated as well. They're much more syntactic convenience than true semantic variation. Typically, variadic functions encode defaulting which, in Haskell style, is just ignored. Otherwise, you just encode them as separate functions with different names. That can be annoying, but in my experience it rarely is. Worst case, you can often abstract over most of the polymorphism using a typeclass.

I'm sure you could manufacture some Clojure code which takes advantage of non-obvious macros, bizarre variadicity, and massive dynamic typing... but it'd be really hard to understand as a human.

Human intelligibility tends to drive Clojure code to be easily translatable.