>>12497226Of course it goes in both directions sometimes but female larger dimorphism is overwhelmingly dominant in animals and there is a reason for this. Even in mammals, where it actually makes some sense to invest a more resources into the males, a non trivial minority of mammals have female larger dimorphism and they exist in a range of environments.
Basically the only reason for male larger dimorphism is sexual selection. In terms of utility it is never a better trait than female larger dimorphism. Like as an example, lions would not have lower fitness if the lioness' were bigger than the males. The opposite, males would no longer be able to kill the babies of other males.
When males are larger it's a sign that the species is trash. The females are raped, the children are killed, and males have to spend all their time pissing all over their territory and beating each other up. It sucks for everyone.