[azinman2]

First notice how "pretty easy" isn't the same as straightforward. Good luck getting my mom to figure it out.

If you lose your phone, upgrade to a new one, or erase and restore it you lose all your authenticator credentials. That doesn't happen with SMS.

If you're in a situation where security is paramount, then physical cards or authenticator are a better way to go. If you're 99.9% of the population, Sms is a far better solution.