Could be as simple as humans get so many neurons and need to allocate them across total set of stuff needed for life.
Women need to devote a good % of those to pregnancy mode, while men just have normal mode.
Therefore some functions may have to deal with reduced neuron allocations, because the 'missing' ones are required elsewhere.
Obviously a simplification of things, but with only one way of needing to be men optimize to a different configuration with a different allocation of neurons to match.
We never actually used large numbers of monkeys paired with typewritters to produce new literature.
Why? Because it would have wasted all the bananas to produce a bunch of shit.
That is all this level of AI is really equivilant to.
Throwing pudding at a wall, deciding if that toss is closer to the goal than before, changing something, then repeating.
Maybe dont waste the resources until the process is more efficient.