You should watch the show Mr Robot. In the season 2 it goes full crypto, and there is a way of governments vs Bitcoin. The script predicts what I was predicting myself, and that is, a future in which governments want to control 100% what you do with no possible notions anymore for privacy, except they didn't count with bitcoin delivering financial freedom.
They have a cryptocurrency (developed by E Corp) that is closed source and they control everything and they hate Bitcoin since it bursted their Orwellian dream's bubble.
Whoa.. Mr.Robot seems to be the new fap - material

To the OP, countries have already started to create their own coins but who gives a shit. It will never come close to bitcoin due to obvious reasons. There ain't no shit to worry about.
I see no reason for Central Bank of any country create their own Digital Currency? It has an implication to the Economy of one country if this idea is adopted, If we look and check the reason why every country has its own Central Bank simply because of the monetary control as mandated by the Government for single usage of their currency for general circulation. it is use for any transaction, with in the country.