That was a very interesting read. I appreciate when anyone tries to dig into the actual why of culture instead of just leaving it at face value. I get the impression this is more of a working theory than factual on the sociological side, because I do think there's a lot of counter-arguments to be made about strong kinship networks that are otherwise wealthy and prosperous.

And there's a pretty obvious parallel in wealthy nations: the lavish wedding. There are many examples of otherwise modest to low income couples, even with support of their families, putting on weddings they can't really afford but they do it anyway because of social mores. Maybe there's a clear connection between those examples and strong kinship networks. Or maybe its back to peer pressure and keeping up with the joneses.

Social pressure to do stuff like this is enormous in some families. It's not necessarily about the subjects (deceased person or the newly wedded couple) but about re-affirming the status of their relatives. Arguably the dead don't really care. But their nearest relatives definitely do care how they are perceived to be dealing with the death of the deceased. It underlines their importance and status. People come to "pay their respects". There's a whole etiquette around that.

In many cultures it used to be (or still is) quite common to treat brides as property. It's more like a financial transaction than a romantic thing. The groom's family "buys" the wife for the husband. Money changes hands sometimes. An elaborate party seals the deal. A lot of royal houses actually have a rich and colorful history with arranged marriages. And inbreeding because they jealously guarded their power by marrying cousins and managing how wealth and power is distributed via inheritance.

Of course grief and empathy with the mourning relatives is also very real and genuine and is mixed through this. Same with happiness for a newly wed couple.

And some of that empathy translates into people making sure they are there for the mourning family. So, they travel from far. And if everybody is coming, you need to make sure you don't forget to invite everybody else. People will want to be there. And that creates a need for a social gathering. And that in turn results in it becoming a big event. Which then that creates an obligation to make sure that all these people are welcomed properly. They need to be fed, entertained, etc. Or it would look bad on the family.

In short, it's all very explainable. But also a bit irrational to put yourself in debt because you are getting married or because somebody you care about passed away. Some people flip this with not wanting to impose on others with either their marriage or deaths. I'm not married and I don't believe in an after life. I've told my relatives to do what pleases them and works for them with my remains when the time comes but that I otherwise don't really care.