why are there clutch pedals, instead of a grip lever on the shifter?

Wouldn't shifting a stick be better if it was all operated with the right hand, and not the hand and left leg?

I imagine shifting would be faster and smoother, if you used your right hand to operate the clutch, then pull the shifter to the gear you want, then released the lever to enable it.

Maybe a trigger on a pistol grip shifter, or a thumb button on a t handle

Just a random thought that occurred to me while driving, as both of my cars are stick shifts