You can show the progress along a track on a pair of graphs. One graph for how far up or down, one graph for how far right or left. Both from a particular point of view. A single displacement arrow tells you both the up-down distance and left-right distance.
Or you could choose to make a graph of the speeds – One graph for up or down, one graph for right or left. A velocity arrow tells you about both speeds at once. That’s the magic of arrows.
You could plot speeds and distances at once.
Arrows are more straightforward, both as a record of what happened and as a tool to predict what will happen.