This ideology only works in a world where authority as a concept doesn't exist. If humanity ever achieves a global anarchist utopia, then you can try this idea out.

Until then, those with less power benefit immensely from hiding their identity from those with great power. Today, people in many nations live under increasingly invasive surveillance. This surveillance serves to prevent them from reacting to their material conditions (labor organizing, protesting, any sort of resistance).

I think you might agree that anything that prevents a person from adapting to changing material conditions is a bad thing. It creates a life of suffering and oppression that is inescapable. Privacy mitigates this by allowing the oppressed to resist this effect without experiencing the retaliation of the oppressors.

In summary, the need for privacy exists as a hedge against authoritarianism. If humanity manages to organize in such a way where that is no longer a problem, THEN this conversation might be more interesting.