My banking app doesn't even work on the last 3 android phones I tried because it wants a very up-to-date OS which basically means non-Pixel phones more than 2 years old need not apply.

I had this problem and it turned out to be an upstream issue with MicroG which was eventually patched. If you have an error message you can search for existing issues on /e/OS' gitlab/forum.

Revolut stopped working for me for a while with the error that the bootloader wasn't recognised and rooted phones aren't supported. After about a month an OS update solved it.

As long as banking works with web browsers, I think the future looks good for this usage, but I could de-bank my phone and still have plenty of useful things to do with it.

the problem in my case is that the authentication for the banks website requires an app, and that app doesn't work. i am locked out of online banking for that bank because of it. (they also have a windows app that i could not yet get to work on linux/wine)

Ugh. I'm locked up with my bank because of my mortgage terms and being one day forced to install a spyware on my phone really scare me.

Find a new bank. Mine has another problem, so behind they don't support mfa beyond a symantec program I've not heard of before. I don't use it, but can't use my yubikeys either.