Mandatory ID wouldn’t be that bad if implemented claims-based, from within the browser. So that the browser could ask: Hey government, is this user above 18?

Mandatory ID wouldn’t be that bad if implemented claims-based, from within the browser. So that the browser could ask: Hey government, is this user above 18? And the government just responds with yes or no. Sites would then only need to whitelist browsers with this check an merely see an “allowed” claim for whatever type of site they have. Parents or users could use parental controls to “allow” or “block” certain categories, meaning website creators wouldn’t even get any info on the user.