In the U.S., I doubt they'll outright ban cryptos because wall street will want to capitalize on the markets somehow. We've already seen the proposed creation of BTC ETF's.
They'll surely create derivatives like this more and more in the future and wall street loves a good racket. They partially own and control our government (unholy alliance in my opinion) through their enormous campaign contributions and lobbyists so ironically wall street could actually save cryptos from an outright ban.
The government would be stupid to ban trading cryptos because they will theoretically take in tax money from traders with gains whether it's coin to coin or coin to fiat.
But I could be wrong about the US govt in this little rant...they're so dysfunctional they can't even pass a bill that allows them to spend the record amounts of taxes they're collecting right now...