Whatever happened to diminishing marginal utility of money?
It's probably not about money, but about status. There is never enough status, by definition, for an average person. Feminists taught women that having a job is high status, and taking care of children is low status.
(Of course there are also other reasons to prefer job, not only status. People may like their jobs, or at least enjoy the sense of financial security or social opportunities that jobs provide.)
Maybe jobs today are actually quite easy and pleasant, and we just have a cultural taboo against admitting it. I mean, I was surprised when I asked some people about what would they do if they luckily became millionaires and never had to go to work again. Many people responded that without a job, life would be boring. (What, they can't imagine a time-consuming hobby?) So it seems like to some degree people today have jobs to avoid boredom or existential anxiety; and they ask money only because they need to pay their expenses, and as a status symbol. This would explain why so many different jobs have similar working times and similar salaries.
Agreed that status is part of the explanation, and the recent devaluing of parenting effort vs. job effort is certainly contributory.
I'm not sure how to weigh your statement that jobs are now "easy and pleasant" (certainly they're physically less demanding and safer than in the past) with the prevalence of chronic stress and so on. Certainly your millionaire example is weak evidence that jobs are some combination of fun and statusful, though it has the same status-quo caveats as people thinking of the upside of death. Also note the great stress...
As Multiheaded added, "Personal is Political" stuff like gender relations, etc also may belong here.