Board Thread:Naruto Discussions/@comment-30168130-20170706050832/@comment-6769189-20170709130836

Substitutions don't hurt anyone. The objects substituted might hurt someone if it is explosive or has another effect but the main purpose of substitution is to have the enemy waste time, chakra, and resources and distract them.

Gaara vs Lee: Lee lost energy/energy Sasuke vs Orochimaru in the Forest of Death: Sasuke wasted energy pile driving Orochimarus skull into the branch and served as a good distraction while Orochimaru prepared and went on the offensive.

Simply dodging doesn't have those benefits because 1 fighter knows that the other is still in play and will keep their guard up or use less resources. Had Gaara simply slipped out of Lee's final attack Lee would have bailed on it and tried to catch Gaara again, but since he substituted Lee used the last of the time/energy he had with the Gates which was what ultimately lead to his defeat.