You can do good and bring peace in Sword & Sorcery. Benevolent heroes can make a big difference for the better. However, you can not change the world. You can only change the immediate area which you directly control. In Sword & Sorcery, you don't improve peace and safety with education and financial support to the poor, or by appealing to peoples better nature. People have no interest in equality of wealth or power. Everyone wants to be richer and more powerful than anyone else. The only way to make people get along with each other is to force them. You can't reform a city by exposing corruption and promoting cooperation between the benevolently minded lords. You have to make them submit to your rule by force or destroy them if they resist.
In Sword & Sorcery, you can bend society to be safer and nicer. But you always have to keep the pressure on them. As soon as that pressure is gone, everything will spring back to the old ways of greed and violence.

Bringing change to a land or city does not happen by protesting, debating, negotiating, and compromise. If you want to change things, you have to walk up to the king, cut of his head, and throw it down the palace stairs. All the other people in power are given the choice to take what you allow them to keep, or lose even that as well.
Sword & Sorcery does have a place for good, but not for democracy or pluralism. Be it good or evil, the only form of functional government is dictatorship.