Your one sentence tells that you are closing your eyes towards facts: “Religions have not "declined into divisiveness". More people = more religions. Also nothing to do with evolution. Nothing.”
Religion goes divisive once its founder leaves the stage (1 Corinthians 1:12, 13). It has nothing to do with population increase.
Also question arise—why should religion go divisive if population increases? Also, what did over 41000 Christian sects accomplish by being divisive other than giving a massage to their collective ego?