Any underdevelop country are prone to corruption and yes you are right blockchain project might not help to grow your country's economy since the government itself needs to fix first. But with the help of cryptocurrency, people might start to change their economy unless of course, they have to stop supporting corruption in their own country.

Anyway, if your government didn't ban any cryptocurrency in your country then you still have a chance to make a change it but it does require a lot of people power to change your whole country.