Fiat currency its a currency that a government has a control while crypto can not be manipulate and can not be created out of thin air. If people adopt a crypto currency then the fiat currency price will plummet. Its one of the reason why government impose a stricter rules in cryptocurrency.
In short, the government wanted to be in control on everything especially in terms of money. The government think that if everything will be on their control, it will be okay or the market stays stable. Not really the market but the economy will be on their power. But as we can see, there is nothing happens in the economy. Go up or go down, the worldwide economy is still not good.