Government IDs are not a solved problem, and you don't seem to have even tried to consider the issues involved. The key distinction between voting and cold medicine is that you have a right to vote, but not to buy cold medicine. So if you lost your ID, or it's expired, it is not an option to just say "that sucks, I guess you can't vote now".
In fact, as a rule, ID is reserved for things that aren't important, because it is a point of failure.
The point of India requiring identification for benefits is to prevent waste and fraud. And given the number of poor people in India, and the limited amount of money they have to help them, it seems like quite a good thing to do so.
Identifying people is not hard, even for the poorest countries, and it's quite easy to do with modern technology. There is no good-faith reason to oppose it, any more than there is to oppose driver's licenses.
Did you read the article I linked? You keep saying this is an easy thing to do, but don't seem to acknowledge any of the problems it causes. It is not easy to identify people. It is easy to identify people with 99% accuracy. If the remaining 1% are unable to access society, that is an unacceptable risk.
Consider for instance the people who currently exist, don't have government ID, and don't have an accurate record of their birth. Such people exist. Should they just die, or something?
If you don't have a birth certificate, there are other ways to get an ID card. Immigrants do the US do it all the time. Pretending this is some unsolvable problem is ridiculous. It's like saying we can't collect taxes because it's impossible to identify people. When the government needs money, suddenly it's very possible to identify everyone and send them bills. Funny how that works.
In fact, as a rule, ID is reserved for things that aren't important, because it is a point of failure.