On a full world map (Small Scale), you need to be using a Mercator projection for a compass rose to be appropriate, and a scale bar will only be appropriate for an equidistant projection, in which case it will still only be appropriate for specific measurements (Through a certain point or along a certain axis)

The example map with the tutorial is in Plate Carrée projection. Direction is not preserved, and distance is only preserved along the vertical axis. The compasses and Rumb lines are inappropriate, though a simple north arrow would not be, and although you could arguably use a scale bar for measuring distances north-south, it would be misleading unless you added a note to indicate that restriction.