Phrases like "peaceful tribes" often denotes ahistorical readings of the past.

Consider American history as a for instance.

Plenty of native American tribes were much more warlike, much more violent than the Europeans that displaced them not by being more warlike but by being more efficient at warfare.

Relative communal living on this continent without the same concept of land ownership imported from Europe still resulted in plenty of violence and war as the stronger tribes pushed the weaker ones to less desirable land through applying force, consistently. Brutally. Often employing terrifying tactics like torture and rape to make the point.

If anything, I feel like the society that displaced what modern people assume were peaceful tribes is significantly more peaceful than most of those tribes were specifically because of the structure of our society.

I'm all down with people, especially smaller groups of people, pooling resources for mutual gain. That's essentially what families are. But such groupings can't get too large before it becomes apparent what the advantages of individuality and self interest for the benefit of collective interest are in the real world.