For each person his mental and physical energies respond to and act on macrocosm the mind and body themselves being illusory with reality grounded in deepest self being the Atman. Any projection or illusion from a reality is finally assimilated into that underlying reality.
Why this play of projection and assimilation? Why not just the timeless reality?
Cooperation, growth, consummation , fulfilment for example are relative and cannot be in a reality which has nothing to compare to. These attributes must be important to reality and so reality is the way it is