When a translation doesn't require a block confirmation, there ideally should be no transaction fees either. Also the architecture will not be decentralized like Bitcoin. I think in crypto market, we already have couple of options where are transactions are nearly instant and cheap. But if you have some idea to make it instant and free, pitch your idea to government. They might accept it.

before doing that, study the architecture of UPI payment system that are being used in India. That's the only thing you will have to compete to.