You're strongly forgetting that a lot this mentality is reliant upon a society that still needs to survive all the basic dangers that Nature throws at it, and have hid it behind the word of "comforts". We've eradicated most common diseases and have overabundance of food in the West. The only remains of difficulty is monetary wealth to maintain survival, hence most of the urgency has dissipated. There's instinctual behaviors that maintain most of the group mentality but it's no longer necessary if one can survive alone.

Also we're realizing that throughout history most men never get or had gotten to reproduce. All the remaining ones either get killed in war or famine or by other means, but since post-scarcity has eliminated most of these issues, you have millions of idle hands just trying to survive on their own. The current state of technology has affected society such that it's incompatible with the old agrarian instincts. Excluding passing on genetics, most don't feel the need to follow the ancient rules, because why? The government also subsidizes overpopulation of detrimental groups that dilute the gene pool as the refuse adds and mixes their garbage genetics to it.

Most are going to die under this system eventually, whether the government intentionally kills them to free up resources or society falls apart from lack maintaining it. A lot of faggots here will get their wish of returning to group/tribal survival, it will just cost millions of bodies.