Keeeep going.

Are banks POWERFUL? Do they have lots of money and/or connections to those who do? Do they have a vested interest in getting transactions right?

Absolutely!

Now, with all that money and power -- they -- whoever THEY are, need to come up with smart ways to verify transactions that don't involve me giving them all the keys to all my devices.

We have protections like this elsewhere - even when they have some "ownership." The bank kinda owns my house, but they still can't come in whenever they want.