Regarding banking apps. A relative bought a Huawei just as they were pushed out of the western market and it turned out that it was shipped with a Android fork with a Huawei store. Most things worked fine, but banking apps was a problem because they could only be installed through Google Play or App Store.
The solution I found for her was installing a virtual Android environment with Google Play. So when banking apps are needed she opens the virtual environment.
I don't know if this solution will continue working, but it works for now. Guess I will find out.
I have been looking into Fairphone for work. My focus for that is mostly long lasting, repairable, hardware. I want a minimum of friction with switching the users, so it would be Android for us, but I think there are open non-Google options.