Why Saves Outweigh Likes
Recommendation systems have a persistent problem: the cheapest signals are the easiest to inflate and the least informative. A like takes a fraction of a second and can be given absent-mindedly while scrolling. It tells the system very little about whether the content was actually valuable.
A save tells it a great deal. The user stopped, made a deliberate decision, and filed the video away for a future purpose. Nobody saves something by accident. That makes saves a costly signal in the technical sense — expensive enough to produce that they are hard to fake at volume and therefore worth weighting heavily.
The practical effect shows up in how videos age. A video that collected likes tends to peak within a day or two and then flatten. A video that collected saves often gets picked back up days or weeks later, because the system has been told it has lasting value rather than momentary appeal.