Do you really believe that banning cryptocurrency would be "easy"?
What is this "cryptomunitions" you're talking about from the 90s...?
I suppose the highest leverage card that legislators could play to try to hurt cryptocurrency would be to put a stranglehold on the fiat currency on/off ramps (eg making businesses like coin base flat out illegal), but even after doing that peer to peer markets would survive (albeit likely after also taking some damage to user base, maybe).
It'd also put a dent in crypto as a perennial pump-and-dump investment scheme, which in the long run would probably be quite good for its ability to actually work for daily, legitimate use.