In RCE you can right click a folder and get a delete option.
However the delete option only appears if there is content in the folder. This allows you to delete a folder and everything it contains in one shot.
If a folder is empty, the delete choice does not appear. Meaning you can't delete empty folders, only folders that have something in them.
This is incredibly dangerous. You should only be allowed to delete empty folders, not the reverse. (Also - the New Folder choice doesn't work on an empty folder. You have to create a report or dashboard first, then you can create a new folder.)