But we don't have anything like FF as an alternative to go from Android. Especially considering banks require "certified OS".
ATMs won't let me send money or do any other kind of maintenance
Oh, and you can always send money by withdrawing cash and giving it to the other person physically.
Or go to the bank branch, or write a cheque.
I won't travel to another city or country just to hand money in cash.
I won't travel to a branch to... I have never ever written or received a cheque, what the heck even is a cheque? A piece of paper someone can photo-copy?
I used to be able to do all of my banking from a web browser, from any browser/OS I liked. I've had a fob that displayed a 6-digit code rotating every 30s. This used to be simple and secure. What you propose is ludditism.