It only depends on if it's a social contract, which implies some localized majority. You may believe your ideals are the best in the world, but I assure you many other people with vastly different ideals than your own believe differently with just as much, if not more, conviction.

You can't simply beat your chest and claim superiority and thus we need competition of ideas. E.g. the most prosperous happy places on earth tend to have social contracts that look out for groups such as women, homosexuals, etc.

You can't simply prove an idea is better by appealing to your own sense of morals/justice and if there's no evidence that some ideals are better than others, how would you reach consensus anyways?

In order to make everyone share the same social contract you either have evidence based progress or authoritarianism and historically the evidence suggests authoritarianism doesn't pan out all that great.