But in the mean time the value is likely to have tanked, because if they can't trivially be traded for national currency, the interest in them will wither.
This is the thing that has always bugged me about cryptocurrency - people are only passionate about it because they want to make more traditional currency with it. Then they adopt this "decentralized" rhetoric. It's always felt hollow. If owning/trading bitcoin became a crime, it'd be done.
Ever since Dogecoin had a moment, there's now a million coins trying to engineer their own "moonshot".
This is on top of the security issues and of course the energy issues. Cryptocurrency is garbage.