I think this would be an interesting discussion to have alongside the the sahm one.
My mum worked in the 70s/80s whilst my gran and grandma looked after us
My aunt worked full time whilst her mil looked after hers
My cousins who work rely on their mum's to pick up childcare
My sil did the same with my mil
I worked around my h for the 15 yrs since we had children, or I used a childminder. It became intolerable to work though 18 months ago. My parents/in laws have nit even babysat for us in a decade and a half.
That's still loads of women picking up the childcare if the discussion is to be had, in my family any way