Because our intuitions have been shaped by Darwinian forces to, as you say, work great in the ancestral environment and still work well enough in today’s society.
What happens if we consider the long-term future, though? Structuring society or civilizations in a way that is ‘moral’ in any common sense of the word is meaningful only from the intuition perspective. E.g. a society that aims to abolish suffering and maximize good qualia does so because it feels right/meaningful/good to do so but you cannot prove by reason alone that this is objectively good/meaningful.
Now contrast this to a hypothetical society whose decision-making is based on the tail end of ‘reason’. They would realize that our subjective moral intuitions have been shaped by evolutionary Darwinian forces, i.e. to maximize reproductive fitness and that there might not be any objective ‘morality’ to be located on the territory of reality that they are mapping. They might start reasoning about possible ways to structure society and progress civilization and see that if they keep the Darwinian way of optimizing for fitness (rather than for morality or good qualia), they will in expectation continue to exist longer than any civilization optimizing for anything else. Thus they would on average outlive other civilizations/societies.
This assumes that it is even possible to effectively optimize fitness through deliberate consideration and ‘do the work for evolution’ without the invisible hand of natural selection. However, even if it is not possible to do this in a deliberate, planned way, natural selection would lead to the same outcome. (of societies with the largest fitness rather than the largest amount of happy people/morality surviving the longest)
Because our intuitions have been shaped by Darwinian forces to, as you say, work great in the ancestral environment and still work well enough in today’s society.
What happens if we consider the long-term future, though?
Structuring society or civilizations in a way that is ‘moral’ in any common sense of the word is meaningful only from the intuition perspective. E.g. a society that aims to abolish suffering and maximize good qualia does so because it feels right/meaningful/good to do so but you cannot prove by reason alone that this is objectively good/meaningful.
Now contrast this to a hypothetical society whose decision-making is based on the tail end of ‘reason’. They would realize that our subjective moral intuitions have been shaped by evolutionary Darwinian forces, i.e. to maximize reproductive fitness and that there might not be any objective ‘morality’ to be located on the territory of reality that they are mapping. They might start reasoning about possible ways to structure society and progress civilization and see that if they keep the Darwinian way of optimizing for fitness (rather than for morality or good qualia), they will in expectation continue to exist longer than any civilization optimizing for anything else.
Thus they would on average outlive other civilizations/societies.
This assumes that it is even possible to effectively optimize fitness through deliberate consideration and ‘do the work for evolution’ without the invisible hand of natural selection. However, even if it is not possible to do this in a deliberate, planned way, natural selection would lead to the same outcome. (of societies with the largest fitness rather than the largest amount of happy people/morality surviving the longest)