Do you think BTC will be merged with something that is associated with traditional currencies? What government would do that aside El Salvador maybe? 
What do you mean by merged with a traditional currency? Do you mean backed by a traditional currency, the way stable coins are, if that is what you mean, then it is not possible, that is not how bitcoin was created, if you want a cryptocurrency that is backed by traditional currencies, then go for USDT, USDC, etc. That being said, El Salvador made bitcoin a legal tender, but no entity or government can make any arbitrary changes on the bitcoin network, that is why it bitcoin is decentralized.