In the desktop web version of YouTube, if you close the browser while you are watching a video, you will then see this the next time you visit YouTube:
This is a typical example of “dark pattern” i.e. a feature that is useful to the website maker (YouTube wants you to be hooked on watching videos to maximise their ads revenue) but hostile to the user (you closed the browser tab because you didn’t want to watch the rest of that video, but you get force-fed that same video once again).
Thankfully, the browser plugin uBlock Origin comes to the rescue. Go to uBlock Origin’s Dashboard, click on the tab “My Filters”, and paste the following:
Now, when you visit YouTube, the hostile feature is gone.