If you didn't explicitly install and grant permission, it doesn't run on Graphene. It's such a nice default.
Well, it's not a big problem, because most of the bank apps still work, but they rely heavily on Google Play Services. It can partially be solved with a separate profile and Graphene's sandboxed Google Play Services, but still a bit annoying :(
What's confusing about disabling any Gemini integrations in your apps? Don't want Gemini to access todoist? Turn it off or deny the permission or whatever. So scary. This is basic Android 101.
Specifically, Ally, Cap1, BoA, and my local bank all only make me do SMS/email nags at worst. If any of them started pushing trash like expecting to force me to install their app on my actual in-my-pocket-when-out cell-plan phone, I'd drop them like a bad habit.
I've never really had a problem with unauthorized transactions, and I'm generally not squeamish about random online retailers (though most seemed to have moved to Shopify, shrug). Generally the most important thing you can do to protect yourself against fraud is review the transactions on your account within 30 days, so any feature that makes it more difficult to do this actually hurts you.
Traditional bank accounts are quite close to an open ledger - the only thing one really needs to initiate a transaction against an account is the account number, which is printed on every check. As I said, the biggest fraud risk is not checking your accounts every ~30 days. Do this, and your liability is basically capped at having to fill out some paperwork and change account numbers.
The "Rube Goldberg contraption" is to mitigate the nonconsensual SMS nag by making it as easy as possible. My login security relies on my passwords. If someone can get those passwords, it means they've pwned my computing infrastructure and I have got much bigger problems than cleaning up unauthorized bank account activity.
As for GVoice, I chose to start using it because I saw Google and AT&T as similar attackers. I've stuck with it because it works for more of these types of things than other VOIP providers. With "AI" that original calculus might be changing, and if (when?) I decide to jump away from that then I'll probably move towards something like @rsync's "2FA Mule".