Look at it from the other side - not all jobs are really all that “fulfilling”, either. Plenty of folks who work aren’t doing something they really love, or that they seriously think helps society, they are just earning cash to survive.
From my perspective - I’m a lawyer, and a high earner; my wife lost her job as a financial editor and now stays at home with the kid - she seems reasonably happy with this. To be honest, if the matter worked out the other way, I’d have been perfectly happy to switch places.
While my job is not boring, and is very creative in some ways, it is also very stressful and time-consuming. I’ve worked my whole life, but I don’t define myself by what I do. When we were both working, sometimes I wondered if what we were doing made any sense - my wife’s editor job was high-stress as well, and involved getting up early and comming home late; we had to hire a live-in to run the house and take care of the baby. Sure we made lots of money, but we had no time to do anything.
Perhaps the ideal would be to have each of us work half a job, but while there has been some suggestions in that respect in various opinion pieces I’ve read, practically speaking a professional-type job seems all-or-nothing; either work long hours for high pay, or not at all. Having one spouse not working makes a certain amount of sense in that environment, as she or he can then do all the stuff the other one can’t.