Exchange to conventional money like USD and Yen. These can be made illegal. USA has precedent for doing this with gold when it threaten their money supply creat

Exchange to conventional money like USD and Yen. These can be made illegal. USA has precedent for doing this with gold when it threaten their money supply creation ability. If there is no legal ways to convert all these digital coins to fiat currencies, their value will collapse to niche market valuation. It won't disappear completely, just enough to make it small like say total market valuations for baseball or pokemon card collections. Bitcoin technology depends on 1 fundamental flaw that is exponentially increasing demand on energy to hash. Essentially it is inflation of "energy money" to "digital money" for hashing "nothing". The demand is not triggered from population itself but the #1 increasing tech capability, and #2 algorithm itself that double the difficulties of hashing rate. Think of demand of toilet paper, that people need to buy not because they need it but the toilet consume more at a doubling rate whether you poop or not. And then itself become valuable when your neighbor willing to change it for fiat currencies. The moment government make it illegals, the value drop. Black market will exist but then law enforcers specializing to catch "digital exchange criminals" will be established.