here is my theory, religious practices were positively selected not only for their etiological explanation of natural phenomena (thus lowering the stress caused by confusion/cognitive dissonance, which is detrimental for the fitness) or for their role in fixing moral absolutes which condemn behaviours that decrease the overall fitness, but also because the upper classes (priests, divine rulers) could use religion, maybe inconsciously, to fortify their authority and continue to exploit the resources and the labour of the masses, always to preserve their own genome, in a sort of parasitic relationship.

this is also in my opinion the reason elites promote leftism today (maybe unconsciously), they are limiting the access to resources to the to divert them towards theirs.