By tying your service to a smartphone your are basically refusing to provide service if the costumer doesn't agree to Apple's or Google's TOS. If the app doesn't complain about emulation or something different than Android or IOS you are in luck, but that's not the case with most banking apps. And that's only talking about people who don't have it by choice and have money to buy one.
For me, once, it went beyond: I took my first dose of the Covid vaccine, and the second dose's date would still be announced. I asked where it would be available to the nurse, "On the Instagram page of the <local health body>". "But i don't have Instagram" i said, and the nurse shrugged. It requires both a phone and a social media account with your real info, but since absolute nobody complains about it they just do because it's easier.
This will continue as long people are complacent with it. In some places the government is required to provide you services, by law, by any means available and not depending on 3rd party service, but they do require apps anyway and people stay quiet. Phones as an alternative is fine, it's a tool, but should not be an obligatory device for you to be considered an human being.