[jsiepkes]

> A rooted phone can have a modified runtime/kernel that can inject code into whatever processes it sees fit, including Google Pay. Which can expose information being sent to and read from the TEE by the app.

You seem to have now realized (?) you can't modify or see data in the trusted execution environment from the host OS (rooted or not). Meaning the point you made earlier: "means the EMV token store on your Android phone must be in an isolated uncompromised location (usually the TEE)." is not affected by your phone being rooted.

So you have shifted your argument from "the store is unsafe" (false) to "the data in transit to the app might be observable". PCI-DSS doesn't require you to have something like Google Play Integrity API for that.

> The legislation still applies to the bank behind Google Pay.

You started out with that the Google Play integrity API was a hard requirement to comply with legislation (false). Sure, banks are still responsible for fraud under that legislation. But that is a very broad statement which doesn't require Google Play integrity API. GrapheneOS proved you can do attestation in an open way. Google just chose to do it in a way which ties you to Google and further locks down the Android ecosystem.