The thing is that you need to know that totalitarianism is not founded on common sense, evidence and logic. Collectivist ideals are running wild and manifested into a regime seeking to control every aspect of life, supported by some ideologies (a most common one being Marxism and any other versions of it). It is clear that freedom is not only most moral, but also ecomically most beneficial, but logic has lost the battle.
You don't need any logical reason to justify uniforms, the sheer idea of getting rid of individualism (which is oppositional to collectvisim), the goal of equity or any other reason like "terrorists could wield weapons illegally in government unapproved clothing". It could be even, in case of a religious totalitarianism, the reason of sexual exposure - which is currently a quite dominating ideology called Islam.
Let your fantasy run wild, any horror or dystopia you come up with would be realistic (and reasonable) enough - and chances are good that what you brought up is currently, was already existing in reality.
There are no boundaries for insanity and irrationality in totalitarian systems. If it is inefficient and not sustainable - it does not matter - it lasts as long as it is maintained or collapses, which can be decades or even a century. Or forever in the worst case.
The process is roughly this: You create arbitrary axiomes like "being rich means resources have been stolen from the poor" and derive logic from that. It's a house of cards with a foundation which must never be questioned. It has to be accepted no matter what, because if the foundation is lost, any logic derived from that will fall apart. Such thought constructs are called "ideologies" and are widely common in various magnitudes.