Youtube

The traditional square stop-button has been disappearing from media players across the board.

This seems like a deliberate trend; a subtle tactic to keep you "captive" - don't present the user with any obvious option to stop watching and they will be less likely to think to.

Adalytics alleges that YouTube appears to set long-lasting cookies specifically for users who are watching videos labeled "for kids." It also suggested that serves “targeted ads on YouTube videos that are clearly labeled as 'for kids.'"

You can choose to turn on your watch history to get recommended videos, or stick with a simpler home page.