They have terrible support for banking apps and any app that needs play integrity

You are badly informed.

GrapheneOS has full support for Play Integrity[0].

[0]: https://grapheneos.org/articles/attestation-compatibility-gu...

And what kind of support do you think a Linux phone will have? While also having trash tier security. I don’t see that as an issue (for Americans at least since most banks here don’t use NFC/wallets in their apps), just use the web browser to access your bank.

Also GrapheneOS has in my experience decent banking app support outside of a handful of apps (including, ironically, my main bank which disabled GrapheneOS support a week or two ago). There is a maintained list of working apps that you can see for yourself: https://privsec.dev/posts/android/banking-applications-compa...

Then don't use those apps. I know it's easier said than done sometimes, but freedom is more important than convenience.

Does/do your bank/s absolutely always require you to use an app? Is there a desktop/website that you can use? Do they have a brick and mortar location?