What force primarily dictates the overall structure of a supercluster, in contrast to the Local Group?

Answer

The large-scale flow dictated by the universe’s expansion.

When scaling up to the supercluster level, the sheer distances mean that the overall gravitational domination shifts away from internal binding forces and toward the large-scale flow dictated by the universe’s expansion.

What force primarily dictates the overall structure of a supercluster, in contrast to the Local Group?

#Videos

Groups and Clusters of Galaxies - YouTube

galaxiesastronomycosmologyLocal Groupsupercluster