[Mechvet]

Let's take a wider look at the question.

CAN you make a competitive, impressive robot without CAD, and still inspire students to pursue a career in STEM? Yes.

However, I firmly believe in not only inspiring the path into STEM, but also sending students armed with as many useful tools as possible. If you were to try to take a product to any reasonable production team on a napkin sketch, or even a simple paper sketch, you wouldn't get very far (excluding companies with drafters/modelers on hand for precisely this).