Good thinking but to implement it all takes a long time especially for developing countries. If the blockchain system is implemented by the government it is good especially corruption is now increasingly widespread.
Corruption can be used with or without the implementation of the blockchain technology. The cause that the blockchain was created for was to oppose the corrupted governments and banks. If those two use the blockchain technology, corruption will be used as well. I do not think it is good for both of them. Added to that, many countries are still biased about cryptocurrency in general and still have not set a law about it. So, I expect many years to be taken for them to start using the blockchain.