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.
Honestly if there was an alternate and functional phone/OS/app store that early adopters who are a little technical can embrace, it would be the #1 platform in under 5 years. People in the know are chomping at the bit to get away from these big monopolzed platforms, and once it gains steam and polish, people will flock to it.
There are already alternate app stores, and alternate OS and phones that are functional and niche. The real issue is that the Android people knows is not open source, AOSP is the thing open sourced, but thats far from what we use on a daily basis as Android, and Google makes sure every time it can to put hurdles between functionality and open source, some of those hurdles can and are being worked on, some others are out of reach for the open source community