For those interested on the question of age verification and GNU/Linux: be aware that Systemd v261-rc1 was recently released. It now implements an optional birth date field in the JSON user database (see second item under “Other changes”).
The implementation of this field was prompted by age-verification or -attestation laws.
And then people will find another way to do what they want. Similar as they did with the internet as it started. It was not always a commercial cesspool, it started as a very nerdy space and replaced TV as a primary source of information. We can do it again. History does not show a pattern of people submitting, but a history of revolution.
The masses submit; the vast majority submits. When they start to bind it at the hardware level - when eventually a government issued ID becomes required to literally enable hardware to work, then we are all screwed. You can always make your own software but not so much make your own CPU.
Then when they need to deal with the older tech aftermarket so they pass laws prohibiting older tech, it’s all fucked.