Humans are evolved to live and thrive in small collectives with an optimal range of number of individuals within the group.
Alignment of incentives between that of the individual and the group will occur within this optimal range. Conversely, as the group grows in size exceeding the optimal ceiling, it gets harder to get the incentives to align, leading to the centralization of power among the few.
Individuals may search for truth, but groups will always search for consensus. These two are likely to conflict with each other with increased group size. With no consensus, groups fall apart.
Hence, a group can be collectively sovereign up until the theoretical size, after which individual sovereignty diminishes in the favor of the minority which controls the collective. The controlling minority must enforce consensus on the group at the cost of individual sovereignty.