If those input devices are so good, why don't we see people winning e-sports tournaments with them? The mouse (as in a high-end gaming mouse on a high-end gaming mouse pad) is the best positioning device yet invented because it allows very precise positioning with very small movements of the hand. And unlike a pen, you're not constantly fighting gravity.

My arm would get tired quickly if I tried to point to things by pen as fast as I can by mouse.