In my experience there are two kinds of pre-kid people: those who aren't ready for it and those who lie about being ready for it.
I grew up in situation 1 (teen pregnancy) and it is fascinating to talk with my friends about the different environments we grew up in and the different issues (mentally or financially) we face based on that simple comparison.
That sort of arrangement would put you solidly in the middle class at least while having a well-cared-for home and children.
Somewhat contradictorily, it's far easier to manage, teach, and set straight (punish/reward) 15 kids than it is 2. You have to be a falcon for bullying though - spot it from ten miles away and strike it at 100 miles an hour.
Because not everybody is "pre-kid" by virtue of not wanting kids in the first place.
Also, if I feel like it, I can work 80 hour weeks. I just need to rest after doing it and can't sustain it for too long. I don't know if I can't sustain it for too long "because of age", or if because of experience I do now realize I'm doing everything wrong because of burnout, and when I was young I just powered through doing wrong shit when I was stressed out or sleep deprived and didn't asses I was doing wrong shit.