What path you choose though can definitely have an impact. It's been drilled into me that the way you keep working at the job you want is make yourself un-replaceable.

I do believe that knowing more and combining different skill sets can never hurt you. I'm rarely making art, I'm making sausage, hopefully good looking sausage, that pays my bills. I'm not saying illustrators and their illustrations can't provide information, but in my world it's a combination and things move quickly. From this side of the fence I would think illustration is much more an artistic endeavor, while graphic design is more about providing information by combing images and text to give the client what they want. Most of my design time is taking elements and combining them. However, I usually don't have time to illustrate something myself and with the proliferation of stock sites I don't need to.

Part of the curriculum was learning to draw/sketch, so I've become okay at illustration. I went to design school and studied architecture, I became a graphic designer.

Graphic illustrator