I'd wager the only thing you're missing is the high friction involved in setting up a bank account. I've got my credit card stored in my password manager vault, and even if not, I've got that sucker memorized. Contrast that with digging through the clutter on multiple horizontal surfaces in our house to find a checkbook so I can find the routing number and account number, waiting for the two deposits to show up (because I use a small bank that hardly ever shows up on these "automatically authenticate" lists), and then trying to remember what I was trying to spend $1 on...

But that's literally the only problem. The fee structure is AWESOME for micro-payments, so for the right things (small subscriptions?) this could be amazing.