From YouTube, by going to your account then pressing settings, and going down to “manage all activity” and deleting a video from your history, how much will that do? If I watched a brief part of a video and would not like the YouTuber to see that it was me who viewed it, would that delete my name from the views they see?
The YouTuber never knows who is watching. Until half a year ago, the most they could see was your estimated age, gender and nationality, now they can't even see that unless the video has a few hundred views.
Deleting a video from the history will affect the recommendation algorithm in that it's not going to recommend videos based on the video you removed from your watch history.
There are only two scenarios in which a YouTuber knows your name:
- you commented on their video
- you are one of the most recent 100 people who subscribed.