I think the whole premise of your question is wrong. Most countries have a fiat currency. The government via the central bank creates as much money as it need

I think the whole premise of your question is wrong. Most countries have a fiat currency. The government via the central bank creates as much money as it needs to run a society, money is there simply to get things done, it's a promise to 'pay' for work. Money in itself doesn't have any intrinsic value other than the fact that everyone collectively agrees to believe that it does. The government doesn't have to tax anyone, it can just continue to create money and inject it into the economy and things get done. The problem comes that the more money it injects the less the perceived value of the money is (i.e. inflation). It needs to destroy some of the money it creates and it does this via taxation. That's why you have tax.