This is potentially a solution for some but it’s not perfect. If they had a trusted friend or family member who could store backup codes and deliver them as needed, they could probably also just stay logged in on that person’s phone or even have emails sent you that person. Keep in mind that they have limited transportation and likely lose their contacts when they lose their phones, and many will have strained relationships with the housed people in their lives.

A library solution may not scale. Sure, a librarian might develop a personal relationship and do this as a favor for someone. But the author mentions talking to about 30 people with this problem in his neighborhood, which suggests that if word got out a librarian was doing this and they tried to institutionalize it, a library might have to store codes for dozens or hundreds of people it has no way to authenticate.