The problem is that so many people here look at this purely from a USA perspective.
An age check in many European requires no uploading of any ID. It’s an API call toward an ID service, it will tell you which data the service gets access to, and there’s strict regulations and liability around data retention.
I’m not concerned about the government. If they become authoritarian enough to worry, they will impose far tighter surveillance anyway. What we have now is the naive idea that just by not doing ID check, government surveillance is a solved problem in the free democratic world. It’s not. Avoiding ID checks just makes the problem worse because it makes the regular person complacent. The surveillance is implicit and hidden. If we understand that it’s nearly impossible for a non-tech person to avoid being tracked by corporations and governments, then we start working on the things that really help: super tight regulations about what can and can’t be tracked. Requiring audits of large corporations. Solutions that give corporations access to only the data they absolutely need and nothing else (the lack of such things is how we end up by uploading whole ID documents)