It's normally a waste of time to argue about religious or ideological tenets, but today I just feel like it. So here goes:

Traditional socialism, such as you describe, assumes that everyone should have the same idea of what society should be like. It also assumes that everyone understands poverty and prosperity the same way, and that envy can be conquered. Alas, like the other deadly sins, envy is always with us.

You do need leaders if the goal is reach the objective together, with nobody robbed, trampled or shoved aside on the way. Leaders remind people what the objective is, and co-ordinate effort to ensure that those who are more capable help those who are less capable. They also direct community efforts to control the less admirable inclinations to which humans yield all too eagerly.

Socialism is one big counsel of perfection. Perfection is not part of the human condition.