But we don't have anything like FF as an alternative to go from Android. Especially considering banks require "certified OS".
DNB in Norway does for sure. Same for BankID , national electronic identity authorization provider. There are good programmers out there that know their stuff. Find a bank that has a hacker culture like DnB.
I remember that I chose them just by comparing uMatrix output between them and SpareBank - the other big player. DNB had no 3rd party trackers showing, while SpareBank had a lot.