Bitcoin actually doesn't require approval to be used anywhere. You can use it as long as you have internet connection and a device.
Countries "approving" bitcoin just makes it actually legal to use and accept for merchants. correct me if I'm wrong
I also believe that the approval of bitcoin in one's country makes bitcoin legal. Thus, many will patronize the bitcoin as a another form of currency with confidence that the government is not against with bitcoin but is in support on it. The approval can be the first step to create rules and regulations regarding bitcoin to earn more reliance/confidence and entice new batch of investor to enter in the world of crypto.