Anyone can create a currency, but that currency is not going to be an official currency. Only the government can create an official currency that people will make use of. Take for example the United States of America owns the US dollars, it is their official currency and only their government can issue this currency and not just any person.

If you create a US dollar paper money, it’s going to be a counterfeit and no one is going to accept it from you and that’s fact. Now imagine a world without the internet and Satoshi creates Bitcoin as a paper money, do you think it would have been adopted? No it wouldn’t. This was possible because of the internet, but it wasn’t easy move to pull off. And if Satoshi Nakamoto wasn’t good in covering up his identity, I don’t think it would have ended up pretty well for him.