I'd say that ethics define a local and situational landscape of guidance, rather than global policies. There are cases where our ethical intuition breaks down

I'd say that ethics define a local and situational landscape of guidance, rather than global policies. There are cases where our ethical intuition breaks down altogether or gives contradictory answers depending on how you argue, such as the trolley problem, utilitarianism/deontology - and really, many of the great social liberal/conservative arguments are based on different ethical approaches to the same situation. Like the mathematical value of 0/0, it all depends on how you get there. This is to be expected, since after all, we're social animals. Our ethics, such as the sense that murder is generally wrong, evolved and developed over many thousands of years as value systems (via government, law and religion) that preserved cooperative and successful societies. I expect meta-ethics/attempts to codify our ethics, in general, not to succeed, since they never developed as cohesive, all-encompassing systems in the first place. Our society's code of law is as close as we get, and that's a long way off being ethically coherent.