Yes they tend toward zero but on the way down they can either be used to build a stronger more wealthy economy (and fight wars) or wasted in pointless ways such as allowing non productive asset price speculation which only enriches bankers and speculators. China has and is using its fiat leverage in a wealth creating manner, just as the west once did. Governments play a crucial role in building and eroding the wealth of nations...depending upon how well or poorly functioning they are. Sure I hold a good portion of my liquid wealth in sats because its a better bet than dollars, but dollars and because my government and most western governments have so abused their fiat monetary levers I don't want to be part of that however fiat still dominates MoE and so some must be held. Bitcoin gave us the option to opt out of the corrupt neoliberal bankster capture and control of our governments and monetary system, but Bitcoin may not be able to save us from the decline of western hegemony overall that the banksters have in large part caused. Bitcoin is a protest and an alternative and a model for a better system, but is it the whole solution to the decline of western civilisation- I am not sure it is or can be.