There is no way by which you can control bitcoin. But if we use it positively then we can get more advantages form it but the problem is that everybody will not be honest. This the main fact. Due to this problem bitcoin would not be permitted.
Obviously, you cannot control the system for bitcoin, but in terms of regulations you can make the rules so that they don't deviate because nobody wants to break the rules. Even though it is very difficult, with this protection there is at least a fear of breaking these rules.
maybe the government is afraid because it will be used as money laundering from the proceeds of selling narcotics and corruption, but by legalizing it and making clear rules, it is certain that not just anyone wants to do it, at least it will be made kyc to exchange for fiat and vice versa.
precisely the prohibition will have a negative impact and will people look for loopholes to do not comply with the rules.