Long, multi-syllable words delay the message as the mind lingers. This is a real disadvantage in video because the audience must get it the first time through. If your audience is familiar with these terms, it won't slow down the message. Think of the words in a videotape as space travellers. They must journey from videotape to the mind of the viewer with a minimum of interference.
Simple words travel fast and direct, making an impact swiftly.
But complex words must go through several filters in space and in the listener's mind before ever making the desired impression. Simplicity is one of the first principals of good writing. Your writing will improve dramatically if you do nothing more than begin to write simply.