Global conference on countering money laundering and digital currencies

I wonder why no country has ever banned cryptocurrency-FIAT exchanges on their territory. That would really hurt Bitcoin.
They just ask exchanges to apply Know-your-custermers rules, and they track some addresses.

The only reason I can think of is that all those regulators and strategists who are behind them really believe in what they are saying themselves, namely that Bitcoin has too many problems to ever become a world-reserve currency.

Well, they also underestimated Putin, Trump, the voters any many others.

The Emperor to Luke Skywalker: “Your faith in your friends is your weakness”.
Answer from Luke Skywalker: “Your overconfidence is yours”.