I wonder if readers have comprehended my upthread posts wherein I explained that democracy = fiat. We can't eliminate fiat if we retain voting (tallied by and to create a top-down authority) and reputation systems of control, because top-down control over money is the definition of fiat. A top-down controlled digital fiat can be technically secure, but the security is vacuous in the sense it is not protecting us from the power vacuum boogeyman that we were trying to eliminate in the first place. We might as well just continue to use Paypal, VISA, and Mastercard.
Money itself is nothing other than a ledger accounting of the societal consensus regarding how to dispose of the products and services that human society produces in relation to the various degrees of social status that are prevalent among the individuals whom comprise society. Individuals do not produce these things in a vacuum, all production is a consequences of all the moving parts of society working together to serve a greater purpose, to enforce and perpetuate the social contract between the individual and society.
The purpose of top down control is to institute a system that abrogates the consensus of society at large for the consensus of a few who can profit by the situation by imposing the external costs of production on society at large without fair recompense. This is exactly what wasting energy to mine cryptocurrency does. It imposes a cost to society without recompense to society.
That theory is bass ackards.