The social insurance number and the register in and of themselves do not give people access to programs. They have to apply. For the government, the social insurance number has essentially always been treated as a file identifier for government programs. So you have to make an application for old age security. The guaranteed income supplement is generally triggered by an application. So you have to apply for these programs.
I think the challenge for the government is to communicate and make those programs known to people so they make those applications.