Maybe, but as the parity is 1/1, I don't really see what these local currencies are for. I mean what more (or less) than the euro.
Depends on the size of the economy. It can be quite difficult for your government to enact fiscal policies if they didn't have a large enough reserve. The currency and the need to separate them has a lot to do with economics and how countries use currency to stabilize their own economy.
However, there are many places where bitcoin is used. Besides, bitcoin beach seems to work very well for example.
Finally, maybe it's just a ploy by the French government to authorize useless currencies to prevent people from learning about bitcoin?
Nope, tons of reasons. Bitcoin is not user-friendly at the slightest. There has been quite a lot of negative publicity surrounding Bitcoin in the recent months and that contributes to the negative perception of Crypto. In addition, governments are always trying to encourage people to use their currency as a legal tender to better enact capital controls and stuff on their own citizens.
Without the endorsement of the government, people have no reason to accept Bitcoin as a currency.