The resident Guru gives us his opinion on the matter:
Really good copywriters and art directors essentially do the same thing: communicate a message in the most effective manner possible. They both generate and execute ideas. The tools used to accomplish this are different: A copywriter uses language and an art director uses design.
I emphasize the “really good” qualifier because otherwise, you just have a writer and a designer. Not all cooks are chefs. Not all bartenders are “mixologists.” Not all writers are copywriters. Not all designers are Art Directors.
As for what you are meant to be, I guess it all depends on which environment you feel most comfortable working in. Do you have a passion and skill for expressing your ideas with words? Copywriter! Are you more of a visual communicator? Designer!
There’s nothing wrong with experimenting and trying out both fields. Go ahead and see what sticks.