We just need to raise the profile of GrapheneOS and convince more banking apps to use this API, if they are already using Google's attestation API.
GrapheneOS's strategy for raising their profile and being seen as more legitimate is that they've formed a partnership with Motorola Mobility, who will be manufacturing Graphene compatible phones. <https://motorolanews.com/motorola-three-new-b2b-solutions-at...>
Corporations don't use such things for technical reasons. Their reasons are political. They want control. The "security" they talk about isn't the user's security, it's their own security from the user.
> We just need to raise the profile of GrapheneOS and convince more banking apps to use this API
And until they do, GrapheneOS is permanently at risk of being shut out of the market.
And even if they do, it just means we've become dependent on GrapheneOS. They won't trust our keys, only those of corporations. Our freedom is still compromised.