In this way, audiences can watch the presentation like you are presenting it. If you cannot present a slide show personally, it is better to turn the PPT into a video with narration.Your audiences may not have Microsoft PowerPoint to open a PPT but almost everyone can easily open a video with a phone or computer.
Sometimes it is a better idea to save PowerPoint as a video before presenting it to your audiences. PPT is not always the best format to show your presentation.