My local bank requires 9 or above
>Also... even if the app stops working, you can use a web browser still.
It's not uncommon at all for banks to have a website that's virtually impossible to use on mobile browsers.
This thread is discussing a phone with replaceable battery. For at least 5 years.
I think the relevant question is whose phone lasts 6-7 years? Because you might well replace the battery a couple times over the life of the phone and that's fine.
Anyway I just got a whole new iphone 8+ out of a failed battery replacement and it was showing all kinds of OS and application glitches, just as the moto G I had before it did too. The flash and DRAM doesn't last forever, the practical lifespan of the handset itself is about 3 years for complete stability, 4 years for moderate glitchiness, and 5 years for complete unusability, same pattern across both phones.
But yes, this means I will be using a 2017 phone for another 4 years, so the software lifespan probably needs to be close to a decade, and Android's lifespan is absurdly far from that level.
I would not surprise if we'd gradually get longer software support on future phones as time goes on.
I have 5+ year old Android phones that have no issue with banking apps. I'm not sure where this rhetoric is coming from, but it doesn't align with my experience on Android.
Capital one/wells fargo requires android 8+. Citi bank 7.1+. (I stopped looking it up at this point). 8 was released in 2017. So assuming 2 years of major OS updates, that means roughly phones from 2015 can still work with it.
Also... even if the app stops working, you can use a web browser still.
Phone batteries die off long before this becomes a reality.