To be honest, I dont know much about the backend and the overall functionality of Play Integrity.
But from what I see, Google isnt actively blocking anything, right? All google does is provide a verification API that apps CAN access IF they feel they need/want to.
If google would shut down Play Integrity API and remove all boundaries linked to it, banking apps etc. would start developing their own ways of verification, which would probably lead to even more security problems as the data would be sent to and stored on multiple servers with different owners.
Please tell me if im right or wrong on this, as I said, I dont know exactly what happens in the background and what kind of problems you developers are facing in relation to this.