The unvarnished truth is that no child if children could live without food, clothing, physical shelter, access to health care. These necessities all require currency and payment.
It is pretty unrealistic and dismissive to under value the significance of these essential items to a child's very existence. No amount of cleaning ,cooking, event transportation, life management will provide mortgage payment, utility payments, clothing payments, food payments, etc. Not one merchant will accept life administration, a home made mesl, or event trsnsportation for his children as a substitute for actual currency payments .
A parent with an adequate job can pay someone to cook, clean, transport and mind their children. A parent whose contributions are only in the form of home services and life administration is unfortunately most often unable when called upon to provide those other very essential needs. Thus , there is an inherent imbalance. In the sustainable value of what the 2 parties bring to the table, as evidenced by the fact that upon separation the service providing partner is often still reliant or dependent upon the currency providing partner to be able to provide for their mutual children.