There may be several reasons why Er Niu stopped working in Yam Village:

1. Decreased popularity: If the audience is no longer interested in Er Niu's content, or other more popular content appears, it may lead to a decrease in his content broadcast volume and popularity. This may affect his creative motivation and choose to stop working.

2. Commercial reasons: Erniu may choose to suspend the update at an appropriate time to prepare higher-quality content or conduct other commercial activities, such as promoting brands and endorsing products.

3. Decline in content quality: If the content quality of Er Niu declines, the audience may be lost, which may affect his creative confidence and motivation.

4. Personal reasons: Personal reasons may also cause the two cows to stop working, such as family problems, health problems, mental stress, etc.

in short, there may be many reasons for stopping the shift, which need to be judged according to the specific situation.