In one of the world’s fastest growing economies, some 40% of people living in villages don’t have bank accounts, the number rising to three-fifths of people living in the east and north-east of India. (It is another matter that more than 40% of India’s earners have no savings.) One of the main reasons why they don’t have a bank account is that they have no definitive proof of who they are.
Also, identity – when available – is fickle and dubious.
You can’t be a fully-functioning member of the modern globalized world without a legitimate ID.