A number of artifacts have folders to help you organize your items. Folders can be created and deleted and items moved into and out of them. What happens when you delete a folder?
Contents are not deleted, because of concerns about accidentally deleting artifacts unintentionally.
If you wish to delete all the contents of the folder, you must either select all artifacts in the folder and all subfolders and delete them one batch at a time. Alternatively, you can make sure the root folder for the artifact is empty of artifacts (ie only contains folders). Then when you delete the folder in question, all the artifacts shown in root will be the contents of that now deleted folder. It is then easy to select and delete these artifacts as needed.