Why did animals after the chordata evolutionary stage practically uniformly abandoned the hermaphrodite mode of reproduction? In a way what was described in the Bible was an alternate universe where humans had this possibly and possibly Abraham and Sarah was the same person who had sex with theyself and so did Adam and that in many ways has its advantages. Suppose you are an incel but in the Bible universe you could have sex with yourself and raise a baby with yourself that, true, would have your very own defective genes, but at least you would fulfill your biological imperative.