Here's Winston Churchill: “Broadly speaking, short words are best, and the old words, when short, are best of all.”
And this is from Strunk and White: “Anglo-Saxon is a livelier tongue than Latin, so use Anglo-Saxon words.”
Boris Johnson explains it best in this video.
History's greatest orators were masters at balancing simple Saxon words with rhythmic Latin ones. While speaking, they used large Latin words for complex arguments and plain Saxon words for plain ones.
ageofleverage.com/course