Some sites are never removed from Google’s results despite all that black-hat work, so what causes the pages of our own sites to be removed from the results?
Two important things may have happened to you.
Violating Google’s policies
The rules of each country differ from one country to another, and where Google has a legal need for it, it will remove content from search results.
If you believe your site’s pages did not violate the rules, you can request that the pages be returned through the link below.
https://support.google.com/legal/answer/3110420?hl=en
Removing content to protect users and their privacy
Google also removes content that carries very personal information, even when no rule has been broken. Examples of such content include financial or medical information, government information, and private images published without consent.
Because personal data landing in the wrong hands can cause harm, Google gives everyone a way to request removal of content from search results.
Keep reminding yourself of this golden point: if the value of a piece of content is less than the damage it can do to users, the chance of it being removed from Google’s results is very high.
