As much as I’d love to completely get rid of Google/Apple apps, it’s not always possible. My main concern is that I am sometimes required to use two factor authentication apps such as my banking app for example.
I expect these are only available on android/apple store, so my question is, is it somehow possible to emulate android on let’s say pinephone (or any other Linux phone) and get these two factor authentication apps still work?
You aren’t going to get banking apps to work easily. They are determined to ensure that your device is “trusted”. They don’t care about whether you trust it or not. These days a lot of them are using SafetyNet to ensure that the device is controlled by a known OEM. Software-based SafetyNet can be spoofed, but many devices now have Hardware-based SafetyNet which is incredibly difficult (as in there is not a known solution for most devices) to spoof. So if your bank is that annoying then you won’t be able to use the app on any device that isn’t running OEM firmware.
Personally I just use a web browser for my bank. If they are going to try and assert that the device is controlled by someone else than I don’t want to know what other tricks they are trying. The sandbox of a web browser is where they belong IMHO.
I normally use web browser too, but bank imposes 2 factor authentication via their app for sign ins.