Government backed crypto and fiat turned into crypto would be a general trend in the next decade. Soon, every financial sectors including all currency would be on blockchain. Government needs to do it as if they don't, the ease of using crypto would make everyone to dump fiat and national financial bills.
So, in one way or another, crypto is coming from the government itself.
The existing national currency will not go anywhere, it will always be the main form of financial payments, since the national currency of states is part of the state and it interacts with the state economy. Cryptocurrency can fulfill only a supporting role in the financial sector of the state. Do not overestimate the role of cryptocurrency.
On the other hand, cryptocurrency is still developing and continues to search for its niche among means of payment. This seems to be a very lengthy process and we should not rush here.