To become an master speaker requires not only practicing public speaking skill, but an understanding of the elements of great speaking, how and why they work and when to use them.
Observing these qualities in other speakers or seeing where they should have been used but were not can help your own progress. Public speech critique is a tool to help you better see and analyze your own speeches.
When you see someone use the various skills masterfully, you will be able to grow in your skills by imitation. Your appreciation will be enhanced as you see and understand the dynamics unfold as you observe.