Yes, you're right. I don't understand the myopia on this forum when it comes to people spending money irrationally. Human beings are not hyper-efficient savings maximization engines. Every time the story about why "diamonds suck" hits the front page (maybe once a year or so?), the same rounds of patting-on-the-back are exchanged in the comments for rehashing a one-dimensional social commentary that buying diamonds is silly.
Yes of course it's silly! But that's not the point, and it never has been. Once you're at the point of buying a gift that costs far more than its intrinsic, utilitarian value, worrying about its "true scarcity" is just haggling on the details. I purchased an engagement ring for my wife that costed about $30,000. She didn't ask for anything remotely as extravagant as that, but she likes it and I enjoy it for frankly vain reasons. I take immense pleasure out of the reactions it elicits from other people. Despite being very clear-eyed about the artificial scarcity of diamonds and DeBeers marketing, I still bought it because I enjoyed being able to make a frivolous purchase. Personally I don't like spending a lot on things that aren't either experiential or somewhat long-lasting, so I'd never spend much at all on a wedding dress. But I don't begrudge people for spending money inefficiently if they can afford it.
We're all the same species. With very few exceptions, none of us is hyper-vigilant, hyper-rational or hyper-efficient. There are many, many things we idly buy which are artificially scarce or inflated in price. Buying them is not categorically different from buying expensive jewelry under a cultural zeitgeist perpetuated by a global conglomerate. I think most people really don't have much self-awareness about how high their floor of wealth and personal spending is over the ceiling of frugality and efficiency they talk about so much.