Pay securely with an Android smartphone, completely without Google services: This is the plan being developed by the newly founded industry consortium led by the German Volla Systeme GmbH. It is an open-source alternative to Google Play Integrity. This proprietary interface decides on Android smartphones with Google Play services whether banking, government, or wallet apps are allowed to run on a smartphone.
It’s the hardware, and it feels like mobile in particular is intentionally designed to not be modular. I suspect that is by design to keep it under control of the big companies.