It's still worth it to try - I find it difficult to give up completely. Most people I meet are not evil, and it's not like you're going to make it out alive at the end regardless.
Also, according to psychologists, one negative experience outweighs roughly five positive experiences of the same magnitude. So, as we get older, we might have tendency to accumulate negative experiences, and as a result become more cynical and less idealistic. And so it kind of perpetuates.
Underneath, people are overwhelmingly just in it for themselves, and judge others by how closely they align with their personal set of "whats best for me" ideals.
Collectivism means the subordination of individual autonomy to the governance of the collective according to the needs of the collective. You’re a cog in a machine and your purpose is to serve the collective—starting with your family and radiating in rings out from there. I’m not sure Americans can even understand the collective mindset, much less practice it.
I'm speaking about 20 years ago, when getting any kind of peer or social circle respect had the prerequisite of subscribing to socialist utopian ideals, and it wasn't something that was hard to foster in America's dead-end job work culture (which is where you work when you are young). This is urban/suburban America, where most people live.
From what I can tell this was the same with Boomers (they were the OG hippies afterall) and I see the same ideas in today's crop of young people.
The youth however hold little sway over the direction of the country, they're not actually that invested, so by the time they are having an impact, many have already received their first shots of the euphoric side of American capitalism, a career that gives them power and money (after years of wading through dead-end/entry level hell).
American millennials were hyper-individualistic and rejected socially prescribed roles even when they were young. What they wanted wasn't collectivism, it was a higher status within capitalism. Which is why, as you observed, the sentiment evaporated once they achieved that status. I'd make the same point about Gen Z. They want to think they're socialist and collectivist. But they all want to be online content creators and influencers--jobs that only exist in hyper-consumerist, capitalist societies!
This is not a criticism either of collectivism or millennials, by the way. I think Republicans screwed up the concepts during the Cold War era by successfully labeling Democrats as collectivist. What you have in the U.S. is more accurately described as two strains of libertarianism, one that emphasizes social liberty and the other that emphasizes economic liberty.
You define your own notion of collectivism and make claims about how it is necessarily in conflict with other principles, when in reality millennials aren't a monolith, collectivism isn't a monolith, and individualism isn't a monolith. Cultures and subcultures renegotiate the meaning of every -ism they import, and they practice these -isms only as bundles of other, historically correlated -isms.
When the American youth say they want collectivism, they are not saying they want a return to authentic rice farming culture. Most of the time, they are mourning the systematic loss of third places, they are mourning the obliteration of social safety nets, they are mourning the lack of public projects, they are mourning the death of individually influenceable local politics. At the same time, they do not want rigid social roles ordained from above (because "above" is powerful and corrupt). They also do not want a parochial existence taking care of grandma (because the elderly are in greater number and need than ever, and our infrastructure and way of life is ill suited to efficiently meeting these needs). None of this is contradictory cosplay. It is simply a fusion of individualism and collectivism that is unlike that which has existed before, as a result of cultural factors that are themselves unlike that which has existed before.
And the reason I'm quibbling about whether you label this "individualist" or "collectivist" is that it helps explain what happens as these people get older. Why did the seeming collectivism of the baby boomers in the 1960s give rise to a period of extreme libertarian individualism in the 1980s? I think that makes more sense when you realize that what happened in the 1960s was not collectivist, but instead a surge of individualism coupled with a rejection of obligations imposed by traditional society. Viewed that way, it makes total sense how the baby boomers went on to create an economy that was characterized by the rejection of social obligation.
In my collectivist culture, the answer to those questions is "just deal with it." That's the bargain of a collectivist society. The collective will support you, but in return you owe the collective a complex web of social obligations from birth. I happen to think it makes sense,[1] but I'm not trying to persuade you to live in a collectivist society. I'm just explaining the concept.
[1] I'm married to someone from the polar opposite culture: an Anglo-Protestant from the west coast of the U.S. She once explained to our kids that they didn't have to give family members hugs if they didn't want to. She called it "bodily autonomy." I found this concept extremely bizarre.
We can just be people. Don't hurt anyone, no one gets a pass to hurt you. Hurt someone, someone gets a pass to hurt you. Just you, not your "brothers". No matter the status of anyone involved.
Severity, intent, and priors must play a factor in the level of returned hurt, but should never end with none, and death should be a last resort, but never completely off the table.
That's the good-faith interpretation of the golden rule. Instead of the popular abuser and enabler (turn the other cheek) interpretations. They both call anyone who dares hold anyone accountable, a hypocrite for supposedly not following the golden rule.
I don't care what story book it's in, or who said it, or when. It's a good rule on it's own merits. Doesn't mean everything that comes form the same source is equally valid.
I am like that, I stand more on the disillusioned/disappointed side but on the other hand let's not for forget that individuals diverge quite a lot from one another and that for some "Everyone's in it for themselves" has not been a sad conclusion but happy justification for their behavior.
Moral sentimentalism is a fool's errand, because it isn't morality. It's a superficial emotional ersatz, not something rooted in sound reason and reality. And so "universal brotherhood of Man" was always farcical. It's like those people who "love humanity", but can't be bothered to feed the homeless guy on the corner, or treat his wife decently and with due care. It always has to be something "grand" and "out there". It replaces authentic, concrete local allegiances - all relationships are local - with abstract, impersonal "brotherhood", which ultimately destroys real social cohesion.
Yes, there is a "human family". But family and community are not some undifferentiated, homogeneous mass. Society is ordered and composite. While we can love all as a matter of general disposition and wishing them well, love as such is manifested in the concrete and the active, not mere affect or the abstract. Our priorities and duties of love must concern concrete persons. They radiate outward and diminish with distance (by nature, but obviously there is an obvious impracticality to "loving everyone" in any meaningful and substantive way). Your duties toward your wife are greater than those toward your brother; toward your brother greater than your cousin; toward your neighborhood than the next one over. This priority is not either/or, and they do not preclude aiding more distant siblings in an hour of need. Loving one person more than another does not mean hating the other or some kind of license to disrespect the dignity as that person. It does not give permission for jingoism or chauvinism.
In the hyperindividualistic, consumerist liberal developed world, the trouble is that we've become atomized. We have denied our intrinsically social nature (just as collectivism warps it and denies our individuality). In doing so, the social order has been thrown into chaos. That's the chief reason for our social ills. In our misguided desire for "liberty", we have throw away objective morality and the notion of pre-consensual duties. We live to consume, and even our relationships are reduced to transactional conduits of consumption. Our culture is nihilistic; all it knows is consumption. There is no greater horizon. It cannot understand the social truly and in a healthy way, only according to the language of consumption. And all that obstructs unbridled consumption is taken to be opposed to "liberty" and therefore something that must be destroyed.
It's the revolutionary ethos of destruction.
The key here is that favoring doesn't need to mean excluding anything else!
But as I bank years in the adult world, as a worker and a neighbor, I've been progressively disillusioned. I don't find universalism to be a common viewpoint. I've found it to be very rare that anyone wants to be my "brother" or "sister". And sometimes those that seem to, end up being exploitative, callous, or strictly fair-weather.
I'm not resentful or anything. I have a happy family and a few close-ish friends, and life feels full. But I can understand how the loneliness and coldness of the world makes people more particularist. People may think: "if the world acts like it owes me nothing, then what do I owe the world?"