Forces have an effective range. At the sub-atomic range, the Strong and Weak forces act on particles like quarks. Above that is is the electromagnetic force which works at the atomic level to the macroscopic level (normal everyday experiences). After that is the gravitational "force" which works at the normal everyday objects like apples, cars, rockets, and people to galaxies, local clusters, and superclusters. All of the above forces are orders of magnitude stronger than the dark force that caused the expansion of the universe.

So, the space between superclusters is vast and gravity no longer hold sways over the space fabric so it stretches.

One posit is that gravity is not a force but rather a time gradient around mass. The closer you are to the central mass the greater the time curvature so the differential time difference causes you to spiral downward through space instead of an actual field that interacts with a particle (like photon to the electromagnetic field or the Higgs boson with the Higgs field to give us mass).