That's weird because the nuclear family is as old as civilization and the idea of wide social nets that span long distances is relatively new. For vast majority of human history we lived in small tribes and then the family became the tribe to belong to within a civilization. Virtually any institution you could point to is less than a few generations from being mainstream meanwhile family is timeless. I get that some people come from dysfunctional families but that does not discount the rule that by and large they are the strongest source of emotional support and stability. And really, as I've gotten older I've come to appreciate that more and more.

This isn't actually true at all. The extended family is the historically most long lasting form of organisation, people banding together in communities of about 100-150 people, sharing responsibility and living in multi-generational environments.

This was the case until very recently in fact. The nuclear family is largely an abberation brought on by the commercialisation of what used to be the job of a village. David Brooks wrote an excellent piece on the development (in the US in particular) not long ago:

https://www.theatlantic.com/magazine/archive/2020/03/the-nuc...

The dysfunction you're speaking about is actually a result of that very same dynamic. Largely affluent upper-middle classes have replaced the extended family with professional services and shrunk the family unit down. It's poor people and minority communities who, lacking those resources, have suffered the most from the breakdown of the extended family.

The "nuclear family" is an extremely modern concept.The extended family is what is old as civilization itself.Sure, nuclear families existed 5000 years ago. But, it was far more common to live with your extended family.