Does it already have NFC payments (Google wallet alike)?
That's the only thing missing in my opinion.
Discussion
You can pay with you bank app if it supports it or on their forum some people have said that Curve Pay works but I cannot confirm it
I don't live in Europe to use curve.
The only option you have left is to check whether your bank has an app which supports NFC payments
Which is sad. I'm not a silent voice, there is a large number of graphene OS users willing to use their phone's NFC to pay for shopping...
There is not much that can be done. It is not GrapheneOS's fault. Banking system is hard and you can't just develop an app that interacts with it. You need to comply to countless laws, have extremely high security, be certified, etc. Right now you are better off going around with your banking card in your wallet
no. i think a couple one off bank apps work, but generally speaking it does not work on grapheneos