"It's largely because there is no "National ID" system in the US (due to political reasons). That makes it hard for companies to track people, and the SSN is the only number that people consistently have."
> REAL ID is a federal law, not an actual piece of ID. Congress passed the REAL ID Act in 2005. The act established minimum security standards for state-issued driver licenses and ID cards.
"Real ID" is now a thing. It's a "National ID". https://www.dhs.gov/real-id