We have to think of innovative applications of the tech so that it scales up. On the other hand, we have to look at current problems and see which existing technologies can solve them. I am not sure if everyone will agree that blockchain is the best solution for security issues with Aadhaar. Anyone who does not agree with this article which states the following?
If Aadhaar was built on a blockchain platform, most of the concerns could be assuaged as the database would be immensely difficult to hack