#Think of it the other way: Not every user has the same level of familiarity, and other sites don't conform to the same standards.
Think of it the other way: Not every user has the same level of familiarity, and other sites don't conform to the same standards.
Clicking outside the content, or using the esc key to dismiss a dialog vary widely throughout the web.
##Many sites have frustrating dark patterns for lightbox content
Many sites have frustrating dark patterns for lightbox content
Oftentimes dialogs (used to collect email addresses / subscribe etc..) will not dismiss by clicking outside, and keep the close button subtle to force engagement.
People visit your site carrying all of their frustrations (baggage) from past experiences. They may not distinguish between video and other lightbox content.
Nielsen Norman Group an extensive article on overlays
Provide a visible 'close’ command to allow users to return to the underlying page.
Make overlay content accessible to keyboard users (by allowing the Escape key to close the overlay, and by providing keyboard access to content and fields within the overlay).
Keeping a close indicator provides a visible escape hatch, and doesn't impede those who just click outside the content.
