Kathleen Hall Jamieson of the Annenberg Public Policy Center said most modern speeches adhere to a conversational style, designed to feel informal while still being scripted.
https://www.washingtonpost.com/outlook/an-anthology-of-great-speeches-from-the-inspirational-to-the-ominous/2021/07/08/861ba328-5a69-11eb-8bcf-3877871c819d_story.html The Washington Post