When you look at the percentage of people involved in it and people who die to it, we're actually better off than pretty much ever before, even accounting for our vastly improved and devastating weaponry, and even when you look at massive conflicts like WW1 and WW2.
Thing is, a pre-agrarian society means hunters/gatherers, and for that to work out, you need quite a lot of land to provide for a single person (hence why those societies have such low population density). Thus, warfare in that era is all about directly reducing the number of people competing with you for those precious resources, either by killing them or by driving them off the land. And so pretty much all males are involved in it and regular mortality rates from constantly ongoing warfare can reach as high as 20%. Furthermore, warfare itself is explicitly genocidal in nature, e.g. raids of enemy villages, ideally while defenders are away so that you can slaughter as many as possible.
Thing is, a pre-agrarian society means hunters/gatherers, and for that to work out, you need quite a lot of land to provide for a single person (hence why those societies have such low population density). Thus, warfare in that era is all about directly reducing the number of people competing with you for those precious resources, either by killing them or by driving them off the land. And so pretty much all males are involved in it and regular mortality rates from constantly ongoing warfare can reach as high as 20%. Furthermore, warfare itself is explicitly genocidal in nature, e.g. raids of enemy villages, ideally while defenders are away so that you can slaughter as many as possible.