On my youtube front page the first row of videos are: a recent Scott Manley video about some SpaceX thing (which is in my interests), a DnD game (which I have already seen on twitch, youtube of course has no way knowing that), a song from a band I'm listening to since a few days, and a video documenting a glider airplane adventure. All in my areas of interest and I highly doubt that these are the 4 most popular videos on youtube right now.
> Recommendation, as we understanding it, means understanding our interests first.
Yes. And that's what they try to do. Sometimes they fail. For a hypothetical lets say that I recommend to my friend that they should see the new superhero movie in cinemas. They go and watch it and they don't like it. Clearly that means that my recommendation was a bad one, but does it stop being a recommendation? Only perfect recommenders are worth that name?
Your watching a video is only a weak correlate of your preference. If I were recomemnding you something, I wouldnt ask you -- literally -- what specific videos you watch. I'd ask for your (real) preferences: are you bored right now? Do you want somerthing exiting? What's your mood? etc. etc.
Recommendations systems use average expressed preferences (ie., on-average watch frequency) in others to "recommend" you something.
If we didnt opt for such metaphorical naming things would be clearer. Recommendation should, mostly, just be called "Popularity Ranking".