Actually in Australia, IDs usually do get scanned and stored. About the same time I was getting too old for clubs, they were starting to introduce ID scanners. You line up, hand over your driver's licence or passport, they slap it on a wall-mounted scanner, the scan goes into a database and in you go. No scan, no entry. Nowadays I think they just use phone/tablet scanners.
Yes, handheld is now used. If you use the digital licences app on your phone in NSW/QLD the licence details are picked up by a QR code and cross verified via an auth API with Services NSW / TMR QLD. You are also checked against a database of banned patrons, against court ordered exclusions, and police issued exclusions. If you use the physical licence, an extra step of ID —> licence details extracted occurs, then the same process is followed.
I agree that people will lose their identity online if age checks become normalised. That’s not been the case with the club and inner city alcohol venues checks.
In Finland the government has allowed banks to offer (2fa) identification services to those that are using their services. If I sign into a government site using my banking ID, the bank gets paid for providing the service. To my understanding none of my actual ID information is transferred to a party wanting to identify me.
The Linkedin 'validate your identity' was the first time i was asked to actually take a picture of my passport/scan the chip. I'll refuse until they'll allow me to identify with my banking ID.
Actually, in lots of places it was porn sites first, but...
I wish they did, that would be huge.
When uploading ID documents, your account gets tied to your real world identity. That's not a precedent the government should be setting, because private entities having an excuse (the law) to require identification erodes privacy, and because in the future other services could be required to ask for an identification, too. Yes, it's the slippery slope (aka "boiling the frog") argument, but that's how laws that erode privacy evolve - step by step.
Now it's account for social media, then it's porn sites, then it's forums where you might see porn or discussions on suicide, drugs or anything deemed morally hazardous. They might require an ID just to view the site or require the site to not make it public. If (or "when", if we don't oppose such laws) enough countries mandate something like this, most sites will likely require an account for all content, regardless of where the person is located, as otherwise they'll likely have to prove that they've not only geolocated the IP of the visitor, but checked that they weren't using VPNs, Tor or similar services.
As for using zero-knowledge proofs and similar technology to make it less infringing on privacy - I very much doubt the government (any government) to implement this with 100% privacy and security.