I understand you perspective totally, both from historical precedents and todays technology.
....But there has never been a historical precedent for block chain. Ever.
If you think of conversations between royal courts and the clergy ,_ just before_ the Gutenberg press.... (as a comparison).
If governments adopt block chain, and regulate their own currency - and 'outlaw' other crypto's - but the people ignore the laws, make different crypto...make their own trades...
The government can only make laws if the people will obey them.
As soon as they don't, they become powerless..
The clergy et al coming down on the Gutenberg press and free distribution of the printed word, and the bible, didn't stop anything.....
an outlawed fiat based currency is worthless .. just say`n ..