YouTube playlists on channel pages are scrollable horizontally. It's very hard to create a sane horizontal scroll anywhere, but you can at least not break some basic design rules. For example, don't change the type of control element under user's cursor.
Clicking on the arrow will scroll the videos, and if you just keep on clicking without moving the cursor (say, you want to get to the very end), the arrow will eventually disappear as you reach the end, and you'll click on a video instead.
This will load the video page, and once you go back — you've lost your scrolling progress.