Just say that the government will control every single device that's controlled to the Internet and they can add government viruses that you can't remove and they can remotely control all of your devices and brick them if you try to send anything that the government doesn't like.
That's not even an exaggeration, once they enforce OS-level age verification via remote attestation they don't even have to pass a law to do this, they can send a secret order to Big Tech to do this.
I expect the government will require ISPs to only allow connection from approved operating systems that only allow installation of approved apps so we can't do this. Not in the short term, but eventually.
Probably by forcing VPNs to only allow approved operating systems to connect to the Internet via hardware attestation, then those operating systems will only allow users to install signed apps, and only government-approved VPNs will be allowed.
Zero knowledge proofs exist in theory, but none of these age verification laws that are introduced use them, probably on purpose. I'm certain that every government will want to know what sites everyone visits.
but why does it have to be that way. why not have zkp age verification processes anyways, inconvenience aside, what's the harm. If they refuse to let us use them, they need to explain why. I don't disagree with the malicious intent you're talking about but we can have it so that they have no legitimate excuse to require collection of site visit data. all the emotion and fervor aside, why can't we talk about having this as a standardized process that excludes third parties.
Governments are banking on being able to purchase that site visit data anyways, bypassing their own laws that prohibit them to do surveil, we can require them by means of technology to comply with laws and for the last time resolve the "but the children" argument.
The people pushing for age verification have already said that they want to know who's behind every account on every website on the entire Internet. They won't accept any open or privacy-preserving standard.
There is no form of digital ID that isn't evil, but anything requiring attestation is super evil.