https://grapheneos.org/articles/attestation-compatibility-gu...
If the bank is very hard-nosed about it, you could consider keeping an old iPhone or Pixel (because long security updates) for banking if it is practical to do for you. 95% without big tech is also a big win. Of course, if you need to have it with you at all times, that might not be a worthwhile option.
edit: https://privsec.dev/posts/android/banking-applications-compa...