So one use case, where any phone based solutions are a bit off is: when you're travelling. 1. Phone in roaming and no network 2. Battery dying out. It locks

So one use case, where any phone based solutions are a bit off is: when you're travelling. 1. Phone in roaming and no network 2. Battery dying out. It locks you out of using a bunch of services. I had a really bad time when my flight to NYC got redirected to Tashkent and was stuck for 2 days. I couldn't logon to any services. My phone wasn't working, so i did not receive sms notifications i had setup. GMail(and FB and a bunch of others) all thought my account was being hacked and wanted me to verify via my phone or email. So i was stuck in a foreign country, with phone roaming not working, and no way to contact and let people know that where i was. So i've definitely stopped using any SMS phone verification, i'm still hesitant to use Google Authenticator(although i've shifted most of the accounts to it), because my battery tends to die at odd times while traveling.