@GrapheneOS My bank has been this way for months already. They got rid of other 2FA methods they used to support and require a Google-approved Android OS or iOS... even to log in to their banking UI on a desktop/laptop.
It's infuriating, and it means I'm now 100% locked in to a proprietary app on a proprietary OS (controlled by 1 of 2 companies, both headquartered in California, USA) on a proprietary phone for banking and public transit (in Europe), with no alternative possible. 