I’m going to sound like a dreamer and this turned into an essay, but hear me out.
I disagree that you need a complicated financial life to benefit. Once you get beyond pure banking and into the marketplace, open banking has far more possibility.
Car insurance, house/contents insurance, payday loans, mobile phone contract, utility bills, broadband, gym memberships, anything that currently requires a regular payment and a fixed term contract. Opening up transactions, letting an aggregator highlight better deals. That’s a quick win.
Next stage is setting up rules, and letting those do the switching for you. Got a credit card? Let a third party keep an eye out for better deals and if it finds one that meets your threshold - say 2% better interest rate -let it do the switch in the background, transfer your balance and close the old account.
Then for bonus points, why not have that third party give you the plastic card instead of your bank? They can point it at whatever back-end credit card provider they switch you to (a la Curve).
Now you have a robot sitting in the background and keeping you constantly on the best deal, and you don’t even have to swap your physical card.
And that’s just the credit card. And once this is in everyday use, people will think of things that haven’t even crossed my mind (as I read somewhere yesterday, who would have looked at the newly released Google maps and predicted Uber?)
But this is why I reckon you’re looking at 10 years for everything to mature and for the real benefits to start appearing for customers of traditional banks. The full scope is a bit mind boggling.