> The bank's login process has to wait for all of them to respond
Why? If e.g. one loan account is slow to respond seems like letting you in once auth is successful and showing a loading state for that slow account is a better experience
It may be that they've discovered that people feel more comfortable with bank logins taking a while. Maybe if it's too snappy people feel like it's insecure. Sort of like how tax software intentionally adds loading screens to make people feel like it's doing a lot of work behind the scenes even though it's essentially a glorified spreadsheet with instant calculations.
I have no data on this, purely just a theory as to why they may not feel an incentive to make login feel faster.
Why? If e.g. one loan account is slow to respond seems like letting you in once auth is successful and showing a loading state for that slow account is a better experience