Did you know that the subpages of deactivated pages can still be accessible?
If you want to deactivate an entire page tree, it is not enough to deactivate the top page. Every single subpage must be deactivated.
This is because search engines can find pages even if they no longer appear in any menu or link, because Typo3 automatically provides search engines with a list of all available pages.
So if you want to deactivate an entire page tree below page X:
- deactivate all subpages
- Convert the type of page X to a "Backend user area"
In any case: Delete content that is no longer required! Typo3 is not a <s>good</s> archive!