Tap-to-pay is available on GrapheneOS via Curve Pay in the European Economic Area + UK, PayPal in parts of Europe and many European banking apps. Google Pay will likely continue banning using GrapheneOS for the foreseeable future until regulators crack down on Google's overall anti-competitive behavior with Android and Google Play.

90% of banking apps do already work on GrapheneOS:

https://privsec.dev/posts/android/banking-applications-compa...

A growing number of the apps banning using GrapheneOS are choosing to start permitting it. A small number of apps are permitting it by relaxing their Play Integrity API checks but most aren't willing to do that. A growing number of apps are implementing support for standard Android hardware attestation and permitting the GrapheneOS verified boot keys with it. We provide a page guide explain how to do that:

https://grapheneos.org/articles/attestation-compatibility-gu...

Our partnership will Motorola will help get the apps banning GrapheneOS to start permitting it through GrapheneOS becoming more mainstream and eventually being considered the stock OS on certain device variants.