Hmm a slightly different perspective but I think children tend to come along early in relationships and before either partner knows how the other will react to major life events because they have never before encountered them: birth, a traumatic birth, miscarriage, neonatal death, a chronically unwell infant, a work crisis or crisis of confidence, the death of a parent, etc.
Over time couples learn each other's strength and weaknesses, how to manage the other and the art of adjustment and compromise.
DH had all the signs of a workaholic before marriage. When DS was born he went into overdrive and just said "so far they money has been yours, now I have to make as much to make sure our children are totally secure. And he did and for the next 20 years or more I took on everything at home pretty much single handed but things like housework were never a problem because he never had the issue paying with paying someone else. He did always go to football on Saturdays (season ticket and corporate stuff) but I got a lie in on Saturdays and where he could he took the dc out on Sunday afternoons. It wasn't long until he took ds to football with him either.
However, he never did night wakings and I didn't want him to because I had the luxury of being a sahm and basically doing something I loved. It might have been different if ds hadn't been unwell as a baby (chronic asthma and ears) and if I hadn't given up work but at 35 I was burnt out (trading floor) and dh was pretty much just beginning the rump of his career.
I went back to work when dd started school part time at first - nearly 20 years ago now and I think that invigorated our marriage and gave me a sense of being and individual purpose. Although nothing changed at home: DC had childcare and I continued with the domestic organisation. But our individual input was always equal and that's what made it fair.
Over the years however many many women scoffed.