"debugger vendors in 2047 distributed numbered copies only, and only to officially licensed and bonded programmers." - Richard Stallman, The Right to Read, 1997
I only have Linux PCs (laptops) and servers, 100% of my work and personal stuff is done there (though for work I do need to hop into MS365, Google Workspace, Zoom, etc, hooray for browsers, my final firewall between me and the walled gardens, though we can have a whole discussion on that).
For mobile, we have PostmarketOS, Phosh, Ubuntu Touch. I really must try living in them, is it on me? IDK, our government even has an identity app for iOS and Android. I should not be using it, I should stick to web. But its so much more convenient. I'm just weak, aren't I?
Maybe I should go for Ubuntu touch, with an iPad on the side or something. At least my most personal device is something I control then. Or just keep my Linux laptop handy (or make a cyberdeck!). But I want a computing platform that does not require carrying a bag. It's kinda sad. Even GrapheneOS (one of the most personal and secure mobile computing experiences out there)'s future is in the hands of its greatest adversary, the one that does not want you to have a personal computing experience.
I cannot imagine a legal defense for forcing someone to accept the terms of service of Apple or Google to use their bank account.
It shouldn't be a thing, but it is. In the Netherlands the newer digital-only banks are allowed to do this. No smartphone, no service.
The more established banks (systeembanken) do have alternatives, but realistically not using their app for login auth and transaction approval is a huge pain in the ass.
(My bank, ABN AMRO, has an app which thankfully works fine on GrapheneOS.)
I barely use my bank's website and could easily not use it at all and still have all the functionality that a bank provides.
In the Netherlands (and beyond) online payments (shops, Steam, etc.) are made via the IDEAL platform run by the Dutch banks collectively. That is a good thing, because payments are secure and easy, and no one needs a credit card. But that does mean using your bank's web service to approve those payments.
Using the bank's offline OTP hardware (where you insert your debit card and enter a PIN and the code generated by the bank's website for an OTP) is possible, but using the app is significantly less effort than that. There is very little point in resisting it. It's not a healthy situation, but it is the reality.
If you install the app then you are complicit in normalizing the requirement of signing terms of service and data sharing agreements to US technology companies in order to do banking.
Be the person that demands better. Be the squeaky wheel. Call politicians and press if needed. Stop this shit now before it becomes expected for school and healthcare too.