Deleted stories are the exception, however: they will only stay in the recently deleted section for 24 hours before they’re permanently removed. To access the folder, navigate to Settings > Account > Recently Deleted.
Clearly, before permanently removing it, Instagram wants to give people opportunities to retain their content. The app already offers an archive or a way to keep posts without being publicly available, and it allows people to keep their posts as an option with this feature, even if they want to delete them initially. Instagram benefits from users having more content, and thus more information. The more people are able to encourage them to keep their posts, the better it is for the service.