I'm not sure about what you're asking, but taking a guess: I think that it's safer to have children raised by a larger amount of figures (primarily the parents, but also grandparents in a multi-generational household, other relatives if they exist, family friends - this would have been other people in the tribe or village traditionally - etc.).
Having all the responsibility fall on two mostly unsupervised, inexperienced people is fragile and "traditional" gender roles do not alleviate this.
The issue with humans is that when everyone has the responsibility, no one has the responsibility. The moment those kids are 'raised by a village' or however many participants of the family, it automatically becomes a lot harder unless, somehow, the tribe is much more cohesive and can reinforce effectively the same rules consistently.
<< "traditional" gender roles do not alleviate this.
I would personally argue that the "traditional roles" seem to help the offspring on several levels, but I didn't see many studies ( as opposed to non-traditional that is ) to that effect.
I think most would agree that more is better than fewer caretakers. This works well when families are located close geographically, but not so much when spread out.
I would also argue, why does the community automatically bear the responsibility for a decision made by two?
They also pay taxes for schools etc. - we're talking about society-wide outcomes. Personally I have no intention of reproducing and even think that a managed but very significant reduction in population would alleviate a lot of issues, but this doesn't mean that I want existing children to be mistreated.
My view of life and society drastically changed for me once kids were in the picture.
With all due respect, Given that you’re on the path to population control and all that’s implied with that, I find it difficult in myself to take what you say seriously.
Having all the responsibility fall on two mostly unsupervised, inexperienced people is fragile and "traditional" gender roles do not alleviate this.