> "Well that's not really true. There's most definitely functionality that is only available in the app. If I want to make a payment without having to dig a card reader out every single time, I absolutely have to use my bank's app."

Maybe not for you, but you don't know his bank. Obviously I can't pay with my phone if I sit at my computer and use online banking in browser, so obviously payment with phone app won't work if I use browser on phone, for all other online banking functionality there is no benefit in the app, all of my 3 banks I regularly use don't require any card reader or even smartphone, all I need is any phone being able to receive SMS with 2FA codes, if my bank required app to use online banking I would just stop using their services. I am not going to bother with app in the phone while sitting at computer with 32" display and proper keyboard.

So you have to use the other option if you can't be motivated to use the first option? Seems more damning on you than the bank...