Bitcoin is many places is not considered a currency or money but is called a virtual service, so in some places, it's just considered as a commodity rather than as a currency. Of course I am sure governments will try to regulate and control if they see too much money is being drained from their country.
Yes this is absolutely true. However it will be difficult to regulate BTC since it can be stored locally on your device. They can only make the fiat to BTC on ramps ("centralized exchanges") more difficult to access by requiring KYC, though this simply results in decentralized services like bisq becoming more popular since it allows converting fiat to BTC with no ID.
To regulate BTC, they need to regulate the channels where people are trading it for fiat.
They can't have a complete control since bitcoin is design to be a decentralized currency which those who holds it will have total control of their assets.
We might not like the idea of it to be regulated or control but since holding bitcoin is a high risk, the only answer I see is only regulation.