But in oratory, the pauses, the gestures, the tone (none of which can be conveyed in text as successfully) are all a part of the performance. Fir, indeed, it is a performance and, done well, is incredibly strong.

Agreed. Which is why most KC's have studied classical legal rhetoric (in my experience anyway) because studying declamation as an active subject makes you a better advocate. That said, there are fashions in legal advocacy, and the appeal to pathos is certainly done less today.