It's dangerous the same way as fiats may be dangerous - can be used to buy illegal, wrong things, benefits and services. But that way we can ban all money
Maybe because crypto is a digital currency, the way transactions are feer-to-feer, so the government and banks cannot track it, besides there is no income for the country, this kind of transaction can also be used as illegal transactions such as human trafficking, arms purchases, or drug purchases illegal drugs, even though crypto is only a tool, which determines its direction remains human.