[billyp-rva]

It's superfluous because the arrow already points in a direction; the line animation doesn't tell you anything the arrowhead doesn't.

[perching_aix]

On the example animation not all paths are taken, so that is one bit of extra information that the animation does provide. Though even if it was fully identical, I do find it considerably easier to see where the data is moving based on dots tracing out a path than I do by scanning for small arrows in a massive diagram, hence my confusion on this. Fair point though.