Reverse sort was unfortunately never implemented in certain view modes. To enable reverse sort, activate View -> as List. Then select the desired column header to apply for sorting the entries, such as Name, Date Modified, Size, Kind, etc. Finally, select the same column again to reverse the current ordering.
However, if you primarily use as Columns or other views for your folders, then these view settings will be reset each time you navigate to the folder. To work around this, select a suitable ancestor folder and add to your Finder Favorites. Apply View -> as List to the ancestor. Then you can quickly return to the original by descending through this favorite directory root.
Press Option + Up / Option + Down.