I would surmise it’s the opposite cause, people are wealthier now and so kids are less desirable because the opportunity cost is higher.
Most families had only one person working, and one available for childcare. Housing was dramatically cheaper. So was a university education. So was food.
And no - unregulated capitalistic greed has dramatically accelerated in the last few decades. It hasn't always been this way. Corporations are buying up everything so they can extract rent and using algorithms and regulatory control to extract every possible dime. Where before you might rent a small home from a landlord who would understand if you were laid off and had to skip a month or two (and who might not raise rents every year) now you have an apartment owned by equity using software to talk to all the other landlords and fix prices as high as possible who will file eviction if you're a minute late.