I beg to disagree that the nature or essence of currency is consensus, at least not until Bitcoin came. It may be so in a small and primitive community but it cannot be in an advanced and large society.
The fiat currency is made up of a lot of policies, decisions, changes, impositions, etc which are not out of consensus. Of course it could be argued that it is hard to gather the opinions and ideas of everybody and that the very reason why there is a government is that it would act and decide on behalf of the larger population.
However, this is not really the case about fiat. The decisions of the few persons who decide about the direction of the currency are not really reflective of the people's voices and sentiment. So everything is merely imposed on the citizenry whether they like or not.
Yes, the current legal tender system, as you said, does not represent the interests of the majority of people, but is controlled by the minority. This is what I have emphasized in the previous article. The current world currency system is the most unreasonable 50 years in the history of human civilization. Therefore, in the end Bitcoin appeared, and Bitcoin represented the interests of the vast majority of the people. As Bitcoin's global consensus becomes stronger and stronger, more and more people will choose Bitcoin and abandon legal currency.
Given that Bitcoin is created as a reaction to the failure of the government and the central banks to value the trust that the people give to them, it is truly representing the welfare of the people. But since we are talking about consensus, Bitcoin would still be dependent on whether the people would choose to use it or not. Unlike fiat, it is not to be imposed upon anyone. And even if Bitcoin is a fair currency, if the people wouldn't use it because it is still convenient to use fiat, then it will remain simply as an alternative.