Bureaucracies are certainly impersonal, but you'd be at a loss to find one that's genuinely rule based and meritocratic. To the extent that they become remain rule based they are no longer effective and get routed around. To the extent that they're meritocratic, the same thing happens with networks of influence. Once you get high enough, or decentralised enough bureaucracies work like any other human tribes. Bureaucracies may sometimes be effective ways to cut down on nepotism (although they manifestly fail at that in my country), but they're machines for manifesting cronyism.