Nah, just out an outdated inheritance of a narrative.
"Get married, have kids and "settle down" no longer applies to the American Low Class, and it could be argued that with the decaying an dying of the Middle Class here that it's probably on its way out of the Middle Class as well.
That is, strictly financially speaking.
I'm nearly 34, and I know nobody my own age in a happy marriage of longer than 5 years, and also nobody with children that can actually afford both the cost and the time of children.
The financial aspect of it I entirely blame on Richard Nixon, for putting us on Fiat Currency in 1971. Effectively, that means that my entire generation of people were born into a time of financially borrowed time, The only plausible workaround being Nepotism, or literally being lucky enough to just be born into a wealthy family so that you can stretch the dollar out a little longer for yourself, and that's if you play your cards right.
I'm not touching the aspect of why they're more unhappy than not. Elevated dopamine levels and sensory overload play a huge contributor, but so does the decline of the value of the USD via Inflation, as well as the rise in substance abuse and that's just for starters. The gist of it being: How you treat your brain, effects how your brain treats you.
People of my age and younger are brought up on the Indoctrinated Narrative of "the American Dream," because that's what their parents were brought up on, and that's what their grandparents were brought up on. Only now, it's kind of impractical, a bit like stale or spoiled food, leaving a bad taste in the mouth of anybody with the practical sense to place value of objective logic over emotional reasoning, ironically defeating the purpose entirely. Trying to follow through anyways, results in you accidentally trapping yourself while trying to have your cake and eat it too.
Basically what I'm trying to say is:
It's an outdated concept.
Hookup Culture and the rise of sex work though grants no deeper fulfillment, as it's entirely superficial to begin with.
So there's no good answer.
Which is why I stay single, keep to myself, and keep myself suspended with more things to be doing than looking for a partner who sees and understands all of this at this base value. The trouble with that of course, is that this is collected data, there's no solitary compendium or guidebook compiling it all...yet.
Someone might do that, but even if they do, I've got a feeling it'll make more people upset than it will actually try to help guide the ignorant youth in a direction for the betterment of their own survival.