The "Directions" tool in ArcGIS Online/Enterprise allows you to map out a route between an origin and a destination. In Map Viewer Classic, once your route was drawn based on the parameters you gave it, you could drag vertices along the route line to different areas and the route would update/snap to ensure it passed through the place you dragged the route to. It was very useful and allowed for quick edits when the default directions it took were not the ones desired.
In the new Map Viewer, this capability no longer exists. It is a more complicated process of adding stops/creating barriers to get the route to be manipulated and follow the roads you desire. It would be extremely useful to have the older functionality from Map Viewer Classic back at some point, as many routes that get mapped do not necessarily follow the most "logical" path between two places, especially when they are hundreds or thousands of miles long.