that is not true. there are tribes that still exist that they care for everyone in the tribe. many indigenous American tribes cared for everyone to the point that white people were happier in the tribe and didn't want to leave them and became members of the tribe.
Agreed, there were always the few who were selfless, but as far back as we can document there were the privileged and the poor who served and fought for the privileged because they had little choice. That’s what I’m talking about. The powerful using fellow humans as disposable tools.