What happens when your phone dies?
Today's lesson: Print out those backup codes people! Just don't put them on a postit under your keyboard...
Why? Phones die, and the authenticator apps they contain have unique IDs.
1. Your phone dies, and the RSA/VIP/Google Auth apps you have installed die with it.
2. You get your new phone, pop in the SIM, and you are on the phone network again. You reinstall your apps, or restore from backup, at your choice
3. The IDs of the authenticators you installed are *not* restored. Thus, all those sites that used them don;t know it's really you.
4. Hilarity ensues. You can't log in to say that your authenticator has changed without an authenticator!
For now, the sites where I use app based 2FA have backup codes I can print out ahead of time, or a customer service line. But if you are not careful, you can get completely broken.