Output source code:

<iframe loading="lazy" title="How to backup iPhone contacts to PC" width="500" height="281" src="https://www.youtube.com/embed/_Mer1KtiwpI?feature=oembed" frameborder="0" allow="accelerometer; autoplay; encrypted-media; gyroscope; picture-in-picture" allowfullscreen></iframe>

Browser output for users:

This behaviour creates unnecessary paragraphs and if the paragraphs are formatted in CSS with padding/margin, for example, this creates unsightly empty blocks for the user in the browser.

Example: https://iphone-tricks.com/tutorial/4028-whatsapp-how-to-use-bold-italic-and-strikethrough-text

Ticket on WP Rocket inbox: https://secure.helpscout.net/conversation/1451726245/247022?folderId=2952229