Broad-based alignment doesn't come from nothing, but it is surprisingly easy to achieve when a population recognizes a shared stake. A synthesis between selfishness and altruism emerges when you consider who you can call a "neighbor".
Sure. But it takes work for anything larger than a small, close-knit community. I’m pushing back on the notion that this comes naturally and is a default state. It’s not, at least not relative to people naturally forming in and out groups.
The armchair commenters are probably folks who have never organized a group of people before outside a commercial context.
But that shared stakeholding doesn’t naturally drive alignment. You need journalists, fiction writers, organizers and delegates. Travel and curiosity. These each take effort, resources and organization. It’s something we do well. But it isn’t spontaneous in the way small-group kinship is—it literally emerges if you put people in proximity.