Interesting post.
National governments/the State only has as much power as people give them. If it ever comes a time when the mechanism of redistribution becomes insolvent and inefficient at maintaining the farce of economic stability(which is happening), Society will try to correct itself by ignoring the State as much as possible. See black markets/Venezuela/other unstable economies.
I believe also there will be two, general to a degree, competing factions in the world—sovereign individuals versus slaves. Those who have no understanding or technical ability will keep relying on the old order of Statism and use "Fedcoin" or whatever new monetary instrument they push; while the more informed will be using private and anonymous currencies to circumvent any economic oppression.
There will also be regions of the world like Hong Kong that will be considerably de-regulated and even used as geographical locations for the elites and wealthy to store money. Even the people at the top will use the same means as the sovereign types.
At end of day, there doesn't need to be mass adoption especially in the short-term for their to be utility in cryptocurrency, at least at the individual level. As long a demand exists there will be a market regardless of what governments try to do.
RE: Why Cryptocurrencies will fail… eventually.