The only answer I have to that is good governance I’m afraid - in the form of universally agreed human rights (existing examples are of course the Geneva / European conventions, UNHCR etc.).
People have to give up freedoms (to commit murder, genocide etc.) in order to obtain freedoms (to be less likely to be murdered etc.), and I don’t forsee a time when this will just be normal human self regulation. In fact, that seems against nature to me as I’ll explain.
Even the authority lacking ant colony needs to protect itself from new threats - by which I mena it isn’t a utopia that doesn’t involve something that falls between regulation and governance. For example, an external threats, or new dysfunctional members due to “mutations” that cause behaviour that threatens the whole, in which case the regulation occurs through the authority of genes/established behaviours, designed to detect and respond to those occurances. I know this is a subtle point, but such behaviours are restrictions on freedom, in an analogues way to human made laws and regulation - the difference is that one is a product of genetic evolution, the other a product of cultural evolution (both can create good or bad “regulation” / “governance” from the point of view of the whole. If an individual ant could think, and feel envy, greed etc. he might well not want to be a soldier, and have a cushy life milling around the queen :-). But they don’t - lucky ants!
These self regulating systems are not fool-proof though, they can still fail to measure up to existing or new challenges thrown up in nature, and this is why we have diversity in the gene pool, diversity in individuals, and diversity in species (or in humans diversity of ideas, systems of government, governance, economics etc.). So by against nature, I mean that a homgenous self regulating population would not be as robust to new threats, as one with diversity - including what we might regard as dysfunction. If our environment changes suddenly, we might need those psychopaths to save us from an alien invasion (far fetched, but trying to illustrate the point).
Another analogy is the immune system and viruses. Nature doesn’ t create utopias, these are purely human conceptions, a false hope of perfection brought by the human capability to imagine, but which of course is also part of what enables us to improve without relying purely on non-intellectual forms of evolution (e.g. genetic). I agree we imagine these ideas, and that gives us destinations and motivations to work towards. They don’t have to be workable to have benefit, and I would never say don’t dream, don’t imagine, those are amazing human faculties, and ones which I value.
I’m also a fan of utopian ideas. Speaking of imagination, I’m also a big fan of Aldous Huxley. In his final novel Island, he imagines a utopian island society that is very much the kind that you suggest might one day solve our problems. There are lots of good practical ideas in it, but he ends his story by showing how vulnerable the utopia is to the forces that remain outside his island, and I think the message of that is that while we strive towards better, even utopian ideas, we need to be realistic about what is workable, and can survive, or else we risk what we create being crushed by other forces. This IMO includes the necessity for unpalatable means when what we value comes under threat, not just the imperfections of governance, but in the extreme, also violence. Because violence can be aggressive and destructive, or defensive, protective and sustaining.