Fiat currency is the biggest tool of the governments. Well, that and the banking network and big companies owned by Rupert Murdoch’s and Chang Ma’s.
You just can not upset any of the big sharks if you want their business resource and support for you next election campaign as well as economic things such as employment and investment.
The control of the government greatly depends on the strength of the banking system and its operation on fiat currency. Fiscal policy is after all the pivot for economic tension and country’s backbone strength to deal with matters like ideological warfare, health provision and job creation. Basically everything from the welfare provision, to economic activity, to the gritty actions each individual takes everyday such as buying bread or bagels depends on it.
Governments do not hate Bitcoin, Fiat is just there oxygen support system.
Governments control whole nations, theirs and the ones associated by their control on the fiat currency. They use central banks to issue or destroy money out of thin air, using what is known as monetary policy to exert economic influence.
They also dictate how fiat currencies can be transferred, for example poor countries may have very poor banking infrastructure to keep the money concentrated in the hands of the fedualists or the greedy politicians who are out for no good. The poor banking systems mean people can not enjoy globalization as much as perhaps we can.
Government control on the money really enables them to track currency movement, dictate who profits from that movement, collect taxes on it, and trace criminal activity. This is also possible with crypto currencies, tracking bitcoin is perhaps easier because it is super not anonymous.
There are whole organisations dedicated to this fiat currency tracking, whole systems are in place to monitor it. These organisations are also the same ones currently responsible for crypto regulation, and they have to learn a great deal of new and tech-y things that they are not liking.
All of this control is lost when non-government bodies create their own currencies.
Lost control means lost control over so much. If i am paying for my bills with bitcoin and buying pot with the pot coin then there is really an issue of ego that hangs in the governments head. Loss of control really means that the government will need to trust people, be less paternalistic and intervene much less. This also means big businesses will lose their relevance slowly, as more and more ways to make money off of blockchain emerge, as it offers a decentralized solution, that people must push for.
Governments also worry about permission less access to innovation and development. This is threatening to the same revenue pouring big companies that like no competition.
Governments intentionally increase or restrict the amount of money circulating in an economy in an effort to stimulate investment and spending, generate jobs, or avoid out-of-control inflation and recession, as a part of the fiscal policy the whole deal becomes a whole lotta huge! This is even more problematic as rarely any governments understand what they are what they can do in full complexity, they just understand that well you can buy pizzas with bitcoin. Maybe they know more, but they are hysterical and lost in thick clouds of confusion.