Part time/ full time working in a household... As parents.

Not really answering any of your questions, but:

The days of being a parent to a small child are over for me and I'm not in the UK, so my view is strictly of child-care in the US.

I believe that childcare costs are one of the main reasons the birthrate has dropped so drastically in the US.

According to CARE.COM: "Child care has long been one of the largest expenses for families. In order to meet that expense, according to the Care.com 2024 Cost of Care Report, families are using both their savings and their household income." Their CEO further states: "Within the first five years of their child’s life, parents are being forced into a financial hole that is nearly impossible to climb out of,” says Brad Wilson, CEO of Care.com. “A healthy economy depends upon the ability for people to save and spend, but given the crushing weight of child care costs, those pillars are crumbling. The child care crisis should be a major red flag for everyone, not just parents. It is a systemic failure that will impact our nation’s economic growth, and that affects us all.”

[u]AVERAGE[/u] cost childcare in the US is $321.00 per week. Minimum wage in the state I reside in is $14.35/hr. So lets say you work a 40 hour week in a minimum wage job. That is $574 per week GROSS. Take out taxes, Medicare and Social Security to get your net pay, then subtract child care and it becomes apparent that you are working for next to nothing.

According to the U.S. Bureau of Labor Statistics, the average hourly wage of United States citizens as of December 2020 is $29.81, while the average weekly wage is $1034.41. Take out taxes, Medicare and Social Security to get your net pay, then subtract child care.
Anyway you look at it..... It is a big hit to your paycheck.

FWIW: I was lucky, my capacity to earn a very good salary allowed my spouse to stay home when my children were too young to attend school. Once they were in school my wife and I changed positions and she went to work full-time while I stayed home, took care of all the kids needs and simultaneously grew an internet-based business.