The reason for your own currency is you can set your own interest rates to fit your local economy. If you are in a local recession while others are doing well

The reason for your own currency is you can set your own interest rates to fit your local economy. If you are in a local recession while others are doing well you might want lower interest rates, while others need them higher. Both places are trying to make the same balance of inflation vs stimulating the economy - but they need different answers. I'm not convinced it is worth it. Generally world economies are tightly tied anyway and so what is right for large currencies is close enough for everybody. The less coupled you are to the world the more important it is that you can be different.