I believe this is the one disadvantage democracy has over authoritarianism. While China invests and plans for decades, the US plans for the next election cycle. However, authoritarian governments can provide long term, consistent leadership, but their goals tend to drift away from the needs of the larger population to either narcissistic grandiose delusions (such as the great leap forward) or the needs of the few.

I personally see it in terms of risk management. Yes, absolute power would be beneficial if used well, but it rarely is. Democracy reduces the risk of incompetent or misguided leadership. Spreading power out over a larger group with more diverse perspectives prevents blind spots to potential failure. Having multiple parties that have to form a coalition encourages cooperation and discourages extreme behavior.

The 2 party system fails in both regards, it only provides 2 options and therefore reduces the talent pool which harms the potential the quality of the candidates while also increasing risk.

A concrete example is Lemmy itself, the many instances all have their own leadership and the risk of their actions are spread out. When an instance forgets to renew their SSL certificate, others still remain functional. The federated networks almost act as a coalition, except for the fact that multiple approaches are possible on each federated network. When an instance is too strict or has too little moderation, it is defederated by others. The model encourages cooperation and moderates behavior.