My answer may not be completely accurate. There were many reasons why novels disappeared. 1. Expired copyright: The copyright of a novel usually expired after the author had finished writing it. If the author did not renew the copyright, the copyright owner could legally sell, adapt, or translate the novel, causing it to disappear. 2. The novel may be rejected by the publishing company. This may result in the novel not being able to spread on the internet or the content of the novel not being found in the encyclopedia. 3. Site Removal: The novel may be removed by the website because the website believes that the novel is not suitable for their platform or content policy. 4. copyright disputes: the novel may disappear due to copyright disputes. For example, a copyright dispute between two authors may cause the novel to be unable to be distributed online. These are some of the possible reasons for the disappearance of novels, but it is impossible to determine the specific reasons for the disappearance of all novels.