Several of my financial institutions give me the choice of single factor (ID and PW) or two factor authentication. Then they give options for the second factor. Email has always been an option, except now with Capital One. One bank makes a PIN the second factor.

I have a French bank with an odd hybrid. I can access my accounts to view history and balances, or to transfer funds between my own checking and savings accounts, using single factor. This works either on my laptop or on a mobile app. To do anything more requires two factor authentication using two devices.

This may sound surprising, but I know many people who don't have smart phones. They use cheap plans that may not even receive SMS messages, or know what to do with those messages. I even have one very tech savvy friend who has both a PC and a Mac, but no cell phone at all . They do want to use their Macs or PCs for some online banking but would be SOL with Capital One if they weren't home with their landlines.