90% of banking apps work on GrapheneOS. Curve Pay and PayPal provide tap-to-pay in Europe with a bunch of European banking apps also providing it.
Lack of tap-to-pay is currently a problem outside of Europe due to the Apple Pay / Google Pay duopoly for smartphones though. You can use a Garmin watch for tap-to-pay in the US instead if you don't want to use cards for it. Android Wear including a Pixel Watch or Galaxy Watch will also work and can optionally be paired with GrapheneOS.
Lack of tap-to-pay is currently a problem outside of Europe due to the Apple Pay / Google Pay duopoly for smartphones though. You can use a Garmin watch for tap-to-pay in the US instead if you don't want to use cards for it. Android Wear including a Pixel Watch or Galaxy Watch will also work and can optionally be paired with GrapheneOS.